CVE-2026-6861
Memory Corruption in GNU Emacs SVG CSS Causes DoS, Data Leak
Publication date: 2026-04-22
Last updated on: 2026-05-06
Assigner: Red Hat, Inc.
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| gnu | emacs | From 28.1 (inc) to 30.2 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-193 | A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. |
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AIExecutive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The flaw involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Executive Summary
This vulnerability is a memory corruption flaw found in GNU Emacs. It occurs when Emacs processes specially crafted SVG CSS data. A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file.
Impact Analysis
Exploitation of this vulnerability may lead to a denial of service (DoS), causing the application to crash or become unavailable. Additionally, there is a potential for information disclosure, which means sensitive data could be exposed.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are present on your system.
Since the vulnerability requires a local user to open a malicious SVG file in Emacs, network detection is limited. However, you can check the installed Emacs version with the following command:
- emacs --version
If the version is between 28.1 and 30.2, the system is potentially vulnerable.
Additionally, monitoring for crashes or unusual behavior in Emacs when opening SVG files may indicate exploitation attempts.
Mitigation Strategies
To mitigate this vulnerability, you should upgrade GNU Emacs to a version where the flaw is fixed. The issue was resolved upstream in Emacs version 30 with commit 8f535370b9.
If immediate upgrade is not possible, avoid opening untrusted or specially crafted SVG files in Emacs to prevent exploitation.
Additionally, applying any vendor patches or updates provided by your Linux distribution that address this vulnerability is recommended.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The flaw involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer. This leads to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in Emacs. Exploitation may result in a denial of service (DoS) or potentially information disclosure due to the memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
There are no specific detection commands or network signatures provided in the available resources.
A practical step is to check the Emacs version installed on your system using the command:
- emacs --version
Additionally, monitoring for unusual crashes or denial of service symptoms when opening SVG files with Emacs could indicate exploitation attempts.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a version where the vulnerability is fixed. The flaw was fixed upstream in Emacs version 30 with commit 8f535370b9.
Avoid opening untrusted or specially crafted SVG files with vulnerable versions of Emacs to prevent exploitation.
If upgrading immediately is not possible, restrict local user access to vulnerable Emacs versions and monitor for suspicious activity.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS) or potentially information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying attempts to open or process malicious SVG files with vulnerable Emacs versions (28.1 through 30.2).
Since the flaw occurs in the function svg_load_image() within Emacs when handling SVG CSS, monitoring Emacs logs or crash reports for abnormal behavior or crashes related to SVG file processing could help detect exploitation attempts.
There are no specific commands provided in the available resources to detect this vulnerability directly on a network or system.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a version where the vulnerability is fixed. The flaw was fixed upstream in Emacs version 30 with commit 8f535370b9.
Avoid opening untrusted or suspicious SVG files with vulnerable versions of Emacs (28.1 through 30.2) to prevent exploitation.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue is caused by an off-by-one heap buffer overflow and an uninitialized heap read, which happens because the null terminator is written one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Exploiting this flaw may lead to a denial of service (DoS), causing the application to crash, or potentially result in information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
There are no specific commands provided in the available resources to detect exploitation attempts or scan for malicious SVG files related to this vulnerability.
A practical approach would be to check the installed Emacs version using a command like:
- emacs --version
Additionally, monitoring for crashes or unusual behavior in Emacs when opening SVG files might indicate exploitation attempts.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a fixed version. The vulnerability was fixed upstream in Emacs version 30 with commit 8f535370b9.
Until an upgrade is possible, avoid opening untrusted or specially crafted SVG files in Emacs to prevent triggering the memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability in GNU Emacs affecting versions 28.1 through 30.2. It occurs in the function svg_load_image() within the src/image.c file when processing SVG CSS data. The issue is caused by an off-by-one heap buffer overflow and an uninitialized heap read due to writing a null terminator one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may lead to a denial of service (DoS), causing the application to crash, or potentially result in information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
There are no specific detection commands or network signatures provided in the available resources.
As a general approach, you can check the installed Emacs version with the command:
- emacs --version
To detect if any suspicious SVG files have been opened or exist on the system, you might search for recently accessed SVG files using commands like:
- find /path/to/search -name '*.svg' -exec ls -l {} +
- stat <filename.svg>
However, no direct commands or tools for detecting exploitation attempts or memory corruption related to this vulnerability are provided.
Mitigation Strategies
The primary mitigation step is to upgrade GNU Emacs to a fixed version. The vulnerability was fixed upstream in Emacs version 30 with commit 8f535370b9.
If upgrading immediately is not possible, avoid opening untrusted or specially crafted SVG files in Emacs to prevent exploitation.
Additionally, applying any vendor patches or updates addressing this issue is recommended.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying attempts to open or process malicious SVG files with vulnerable Emacs versions (28.1 through 30.2).
Since the flaw occurs in the function svg_load_image() when handling SVG CSS, monitoring Emacs logs for crashes or unusual behavior when opening SVG files could help detect exploitation attempts.
No specific detection commands or network signatures are provided in the available resources.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to version 30 or later, where the vulnerability has been fixed upstream (commit 8f535370b9).
Until the upgrade can be applied, avoid opening untrusted or suspicious SVG files with vulnerable Emacs versions to prevent potential denial of service or information disclosure.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a specially crafted malicious SVG file. Exploitation may lead to a denial of service (DoS) or potentially information disclosure due to memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may lead to a denial of service (DoS), causing the application to crash, or potentially result in information disclosure due to memory corruption.
Detection Guidance
This vulnerability is triggered when GNU Emacs processes specially crafted SVG CSS data, specifically in the function svg_load_image(). Detection involves identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
To detect the vulnerability on your system, first check the installed Emacs version with the command:
- emacs --version
If the version is between 28.1 and 30.2, your system is vulnerable. Additionally, monitoring for suspicious SVG files or attempts to open SVG files with Emacs could help detect exploitation attempts.
There are no specific commands provided in the resources for scanning network traffic or system logs for exploitation attempts.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a version where the vulnerability is fixed. The flaw was fixed upstream in Emacs version 30 with commit 8f535370b9.
If upgrading is not immediately possible, avoid opening untrusted or suspicious SVG files with Emacs to prevent exploitation.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying attempts to open or process malicious SVG files with vulnerable Emacs versions (28.1 through 30.2).
Since the flaw occurs in the function svg_load_image() when handling SVG CSS, monitoring Emacs logs or crash reports for abnormal behavior or crashes related to SVG file processing could help detect exploitation attempts.
There are no specific detection commands provided in the available resources.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to version 30 or later, where the vulnerability has been fixed (commit 8f535370b9).
Until the upgrade can be applied, avoid opening untrusted or suspicious SVG files with Emacs to prevent exploitation.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are present on the system.
Since the vulnerability requires a local user to open a malicious SVG file in Emacs, network detection is limited. However, you can check the installed Emacs version to assess exposure.
Suggested command to check Emacs version on a system:
- emacs --version
If the version is between 28.1 and 30.2, the system is vulnerable. Additionally, monitoring for unusual crashes or memory errors related to Emacs when opening SVG files may help detect exploitation attempts.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection involves identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
There are no specific network detection commands provided for this vulnerability since it is exploited locally by opening malicious SVG files.
To check the installed Emacs version, you can run the command:
- emacs --version
To detect if any suspicious SVG files have been accessed, you might search for recently opened SVG files or scan for SVG files with unusual CSS content, but no specific commands are provided.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to version 30 or later, where the vulnerability has been fixed upstream.
Until the upgrade can be applied, avoid opening untrusted or suspicious SVG files with Emacs to prevent exploitation.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue is caused by an off-by-one heap buffer overflow and an uninitialized heap read, which happens because the null terminator is written one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection involves identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
To detect the vulnerability on your system, first check the installed Emacs version with the command:
- emacs --version
If the version is between 28.1 and 30.2, the system is potentially vulnerable. Additionally, monitoring for crashes or unusual behavior when opening SVG files in Emacs may indicate exploitation attempts.
There are no specific network detection commands provided for this vulnerability since it requires local user interaction to open a malicious SVG file.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a fixed version. The vulnerability was fixed upstream in Emacs version 30 with commit 8f535370b9.
If upgrading is not immediately possible, avoid opening untrusted or suspicious SVG files in Emacs to prevent exploitation.
Additionally, consider restricting local user permissions to limit the ability to open malicious files and monitor Emacs usage for unusual crashes or behavior.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Exploiting this flaw may lead to a denial of service (DoS), causing the application to crash, or potentially result in information disclosure due to memory corruption.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a version where the vulnerability is fixed. The flaw was fixed upstream in Emacs version 30 with commit 8f535370b9.
If upgrading is not immediately possible, avoid opening untrusted or specially crafted SVG files in Emacs to prevent exploitation.
Additionally, applying any vendor-provided patches or updates addressing this issue is recommended.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when processing specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are present on the system.
Since the vulnerability requires a local user to open a malicious SVG file in Emacs, network detection is limited. However, you can check the installed Emacs version to assess exposure.
Suggested commands to detect vulnerable Emacs versions on your system include:
- Check Emacs version: `emacs --version`
- Locate Emacs binary and check package info (on Debian/Ubuntu): `dpkg -l | grep emacs`
- On Red Hat-based systems: `rpm -q emacs`
There are no specific network detection commands or signatures mentioned for this vulnerability.
Mitigation Strategies
To mitigate this vulnerability, the primary step is to update GNU Emacs to a fixed version.
The flaw was fixed upstream in Emacs version 30 with commit 8f535370b9, so upgrading to version 30 or later will resolve the issue.
Until the update is applied, avoid opening untrusted or suspicious SVG files in Emacs to prevent exploitation.
Additionally, consider restricting local user access to Emacs if possible, to reduce risk.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection involves identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
You can check the installed Emacs version with the command:
- emacs --version
To detect if malicious SVG files have been accessed, you may review recent file access logs or monitor for suspicious SVG files being opened by Emacs.
Since the vulnerability involves processing SVG CSS, scanning for SVG files with unusual or suspicious CSS content could help. However, no specific detection commands or signatures are provided.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a fixed version. The vulnerability was fixed upstream in Emacs version 30 with commit 8f535370b9.
Until the upgrade is applied, avoid opening untrusted or suspicious SVG files with Emacs to prevent exploitation.
Additionally, consider restricting local user access to Emacs or SVG files if possible, as the exploit requires local user interaction.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The flaw involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer. This leads to memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in Emacs. Successful exploitation may lead to a denial of service (DoS), causing Emacs to crash, or potentially result in information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection involves identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
To detect vulnerable Emacs versions on your system, you can run the following command to check the installed Emacs version:
- emacs --version
To detect if any suspicious SVG files have been accessed or opened, you may review recent file access logs or monitor for SVG files received from untrusted sources.
There are no specific network detection commands provided for this vulnerability since it is triggered locally by opening malicious SVG files.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a fixed version. The vulnerability was fixed upstream in Emacs version 30 with commit 8f535370b9.
Until the upgrade is applied, avoid opening SVG files from untrusted or unknown sources to prevent exploitation.
Additionally, consider restricting local user permissions to limit the ability to open or process potentially malicious SVG files.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue is caused by an off-by-one heap buffer overflow and an uninitialized heap read, which happens because the null terminator is written one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
There are no specific detection commands or network signatures provided in the available resources.
A practical approach would be to check the Emacs version installed on your system using the command:
- emacs --version
Additionally, monitoring for crashes or unusual behavior when opening SVG files in Emacs could indicate exploitation attempts.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a version that includes the fix for this vulnerability. The flaw was fixed upstream in Emacs version 30 with commit 8f535370b9.
Until the upgrade is applied, avoid opening untrusted or specially crafted SVG files in Emacs to prevent exploitation.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue is caused by an off-by-one heap buffer overflow and an uninitialized heap read due to writing a null terminator one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may lead to a denial of service (DoS), causing the application to crash, or potentially result in information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are present on the system.
Since the flaw occurs when opening malicious SVG files, monitoring for suspicious SVG file usage or attempts to open such files in Emacs could be helpful.
There are no specific detection commands or network signatures provided in the available resources.
However, you can check the installed Emacs version with the command:
- emacs --version
If the version is between 28.1 and 30.2, the system is vulnerable.
Mitigation Strategies
The primary mitigation is to upgrade GNU Emacs to a fixed version. The vulnerability was fixed upstream in Emacs version 30 with commit 8f535370b9.
Until an upgrade is applied, avoid opening untrusted or specially crafted SVG files in Emacs to prevent exploitation.
Additionally, consider restricting local user access to Emacs or SVG files if possible, as exploitation requires convincing a local user to open a malicious file.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is triggered when GNU Emacs processes specially crafted SVG CSS data, specifically in the function svg_load_image() within src/image.c. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are present on the system.
Since the vulnerability is local and requires a user to open a malicious SVG file, network detection is limited. However, you can check the installed Emacs version to determine if it is vulnerable.
Suggested command to check Emacs version on a system:
- emacs --version
If the version is between 28.1 and 30.2, the system is potentially vulnerable.
Mitigation Strategies
To mitigate this vulnerability, immediately upgrade GNU Emacs to version 30 or later, where the flaw has been fixed upstream.
Avoid opening untrusted or suspicious SVG files with Emacs until the update is applied.
Monitor official GNU Emacs and Red Hat advisories for patches and further mitigation guidance.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS) or potentially information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are present on the system.
Since the flaw occurs when opening malicious SVG files locally, network detection is limited. However, you can check the installed Emacs version with the following command:
- emacs --version
To detect attempts to exploit this vulnerability, monitoring for crashes or unusual behavior when opening SVG files in Emacs might help, but no specific detection commands or signatures are provided.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a version where the vulnerability is fixed. The flaw was fixed upstream in Emacs version 30 with commit 8f535370b9.
Until the upgrade is applied, avoid opening untrusted or specially crafted SVG files in Emacs to prevent exploitation.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS) or potentially lead to information disclosure.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
There are no specific detection commands or network signatures provided in the available resources.
Mitigation Strategies
To mitigate this vulnerability, immediately upgrade GNU Emacs to version 30 or later, where the flaw has been fixed (commit 8f535370b9).
Avoid opening untrusted or suspicious SVG files that could contain malicious CSS data.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Exploitation may result in a denial of service (DoS) or potentially information disclosure due to the memory corruption caused by the off-by-one buffer overflow.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
There are no specific detection commands or network signatures provided in the available resources.
Mitigation Strategies
To mitigate this vulnerability, immediately upgrade GNU Emacs to version 30 or later, where the flaw has been fixed upstream.
Additionally, avoid opening untrusted or suspicious SVG files that could contain malicious CSS data.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The flaw is caused by an off-by-one heap buffer overflow and an uninitialized heap read, which happens because the null terminator is written one byte beyond the allocated buffer. This leads to memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file. Exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are present on the system.
Since the flaw is triggered by opening malicious SVG files, monitoring for suspicious SVG files or attempts to open such files with Emacs could be useful.
There are no specific detection commands or network signatures provided in the available resources.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to version 30 or later, where the vulnerability has been fixed.
Until the upgrade can be applied, avoid opening untrusted or suspicious SVG files with Emacs to prevent exploitation.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would primarily involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are present on the system.
Since the vulnerability requires a local user to open a malicious SVG file, network detection is limited. However, you can check the installed Emacs version with the following command:
- emacs --version
If the version is between 28.1 and 30.2, the system is vulnerable. Additionally, monitoring for crashes or unusual behavior when opening SVG files in Emacs may indicate exploitation attempts.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a version where the vulnerability is fixed. The flaw was fixed upstream in Emacs version 30 with commit 8f535370b9.
If upgrading is not immediately possible, avoid opening untrusted or specially crafted SVG files in Emacs to prevent exploitation.
Additionally, applying any vendor patches or updates addressing this issue is recommended.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS), causing Emacs to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability occurs when GNU Emacs processes specially crafted SVG CSS data, leading to memory corruption. Detection involves identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
To detect the vulnerability on your system, first check the installed Emacs version with the command:
- emacs --version
If the version is between 28.1 and 30.2, the system is vulnerable. Additionally, monitoring for crashes or unusual behavior when opening SVG files in Emacs can indicate exploitation attempts.
Network detection is limited since this is a local vulnerability triggered by opening malicious SVG files. However, scanning files for suspicious SVG content before opening them in Emacs can help mitigate risk.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a fixed version. The vulnerability was fixed upstream in Emacs version 30 with commit 8f535370b9.
If upgrading immediately is not possible, avoid opening untrusted or suspicious SVG files in Emacs to prevent exploitation.
Additionally, consider applying any patches provided by your Linux distribution or vendor that address this issue.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The flaw involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer. This leads to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in Emacs. Exploitation may result in a denial of service (DoS) or potentially information disclosure due to the memory corruption caused by the buffer overflow.
Detection Guidance
This vulnerability occurs when GNU Emacs processes specially crafted SVG CSS data, leading to memory corruption. Detection involves identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
You can check the installed Emacs version with the following command:
- emacs --version
To detect if malicious SVG files have been accessed, you may review recent file access logs or monitor for suspicious SVG files being opened.
Since the vulnerability is triggered by processing SVG files, scanning your system for SVG files and checking if they have been recently opened by Emacs could help.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a version where the vulnerability is fixed, specifically version 30 or later.
Avoid opening untrusted or suspicious SVG files with Emacs until the update is applied.
If upgrading immediately is not possible, restrict local user access to Emacs or SVG files that could be malicious.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue is caused by an off-by-one heap buffer overflow and an uninitialized heap read, which happens because the null terminator is written one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying attempts to open or process malicious SVG files with vulnerable Emacs versions.
Since the flaw occurs in the function svg_load_image() when processing SVG CSS, monitoring Emacs usage for opening SVG files or scanning for suspicious SVG files could help.
However, no specific detection commands or network signatures are provided in the available resources.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to version 30 or later, where the vulnerability has been fixed (commit 8f535370b9).
Until the upgrade is applied, avoid opening untrusted or specially crafted SVG files in vulnerable Emacs versions (28.1 through 30.2) to prevent exploitation.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Exploitation may result in a denial of service (DoS) or potentially information disclosure due to the memory corruption caused by the off-by-one buffer overflow.
Detection Guidance
This vulnerability occurs when GNU Emacs processes specially crafted SVG CSS data, leading to memory corruption. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
There are no specific detection commands or network signatures provided in the available resources.
As a general approach, you can check the installed Emacs version with the command:
- emacs --version
To detect if any suspicious SVG files have been accessed, you might review recent file access logs or monitor file system activity related to SVG files, but no direct commands are provided.
Mitigation Strategies
The primary mitigation step is to upgrade GNU Emacs to a fixed version. The vulnerability was fixed upstream in Emacs version 30 with commit 8f535370b9.
Until the upgrade can be applied, avoid opening untrusted or specially crafted SVG files with Emacs to prevent exploitation.
Additionally, consider restricting local user access to Emacs or monitoring usage to reduce risk.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when processing specially crafted SVG CSS data. The issue is caused by an off-by-one heap buffer overflow and an uninitialized heap read, which happens because the null terminator is written one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The flaw involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer, leading to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Exploitation may result in a denial of service (DoS) or potentially information disclosure due to the memory corruption caused by the vulnerability.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
There are no specific detection commands or network signatures provided in the available resources.
Mitigation Strategies
To mitigate this vulnerability, immediately upgrade GNU Emacs to version 30 or later, where the flaw has been fixed upstream.
Additionally, avoid opening untrusted or suspicious SVG files with Emacs until the update is applied.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection involves identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
To detect the vulnerability on your system, first check the installed Emacs version with the command:
- emacs --version
If the version is between 28.1 and 30.2, the system is potentially vulnerable. Additionally, monitoring for crashes or unusual behavior when opening SVG files in Emacs may indicate exploitation attempts.
There are no specific network detection commands provided, as this is a local vulnerability triggered by opening malicious SVG files.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a fixed version. The vulnerability was fixed upstream in Emacs version 30 with commit 8f535370b9.
Until an upgrade is applied, avoid opening untrusted or suspicious SVG files in Emacs to prevent exploitation.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability in GNU Emacs affecting versions 28.1 through 30.2. It occurs in the function svg_load_image() within the src/image.c file when processing specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing the null terminator one byte beyond the allocated buffer.
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file, which triggers the memory corruption.
Executive Summary
CVE-2026-6861 is a memory corruption vulnerability found in GNU Emacs versions 28.1 through 30.2. It occurs in the function svg_load_image() when Emacs processes specially crafted SVG CSS data. The issue involves an off-by-one heap buffer overflow and an uninitialized heap read caused by writing a null terminator one byte beyond the allocated buffer. This flaw can lead to memory corruption.
Impact Analysis
A local user could exploit this vulnerability by convincing a victim to open a malicious SVG file in GNU Emacs. Successful exploitation may result in a denial of service (DoS), causing the application to crash, or potentially lead to information disclosure due to memory corruption.
Detection Guidance
This vulnerability is a memory corruption issue in GNU Emacs triggered by processing specially crafted SVG CSS data. Detection would involve identifying if vulnerable versions of Emacs (28.1 through 30.2) are present on the system.
Since the flaw occurs when Emacs processes malicious SVG files, monitoring for attempts to open or process suspicious SVG files with Emacs could be useful.
There are no specific detection commands or network signatures provided in the available resources.
However, you can check the installed Emacs version with the command:
- emacs --version
If the version is between 28.1 and 30.2, the system is potentially vulnerable.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a version where the vulnerability is fixed.
The flaw was fixed upstream in Emacs version 30 with commit 8f535370b9.
Therefore, updating Emacs to version 30 or later will mitigate the vulnerability.
Additionally, avoid opening untrusted or suspicious SVG files with Emacs until the update is applied.
Impact Analysis
Exploitation of this vulnerability may lead to a denial of service (DoS) or potentially information disclosure.
Since the flaw causes memory corruption, it could crash the application or allow an attacker to access sensitive information.
Detection Guidance
This vulnerability occurs when GNU Emacs processes specially crafted SVG CSS data, leading to memory corruption. Detection involves identifying if vulnerable versions of Emacs (28.1 through 30.2) are installed and if malicious SVG files have been opened.
There are no specific detection commands or network signatures provided in the available resources.
However, you can check the installed Emacs version with the following command to determine if it is within the vulnerable range:
- emacs --version
Additionally, monitoring for unusual crashes or denial of service symptoms when opening SVG files in Emacs may indicate exploitation attempts.
Mitigation Strategies
The immediate mitigation step is to upgrade GNU Emacs to a fixed version. The vulnerability was fixed upstream in Emacs version 30 with commit 8f535370b9.
Until an upgrade can be applied, avoid opening untrusted or specially crafted SVG files in Emacs to prevent exploitation.
Compliance Impact
The vulnerability in GNU Emacs could potentially lead to information disclosure if exploited, which may impact compliance with data protection regulations such as GDPR or HIPAA. However, the provided information does not specify any direct effects or compliance implications related to these standards.
