CVE-2026-14266

Analyzed Analyzed - Analysis Complete

Heap-based Buffer Overflow in 7-Zip XZ Decompression

Publication date: 2026-07-29

Last updated on: 2026-08-07

Assigner: Zero Day Initiative

Description

7-Zip XZ Decompression Heap-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the processing of XZ chunked data. Crafted XZ-compressed data can trigger an overflow of a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-30169.

CVSS Scores

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Meta Information

Published

2026-07-29

Last Modified

2026-08-07

Generated

2026-08-19

AI Q&A

2026-07-30

EPSS Evaluated

2026-08-18

NVD

CVE-2026-14266

Affected Vendors & Products

Vendor	Product	Version / Range
7-zip	7-zip	to 26.02 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-122	A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Attack-Flow Graph

Executive Summary

This is a heap-based buffer overflow in 7-Zip's XZ decompression that allows remote attackers to execute arbitrary code. Exploitation requires user interaction, such as visiting a malicious page or opening a crafted file. The flaw occurs during processing of XZ chunked data.

Detection Guidance

This vulnerability involves a heap-based buffer overflow in 7-Zip's XZ decompression. Detection requires checking for vulnerable versions of 7-Zip and monitoring for unusual decompression behavior. No specific commands are provided in the context to detect this issue directly.

Impact Analysis

If exploited, this vulnerability could allow an attacker to run malicious code on your system with the same privileges as the 7-Zip process. This could lead to data theft, system compromise, or further network attacks. User interaction is required for exploitation.

Compliance Impact

This vulnerability could lead to unauthorized code execution, potentially compromising data confidentiality and integrity. For GDPR, it may result in unauthorized access to personal data, requiring breach notifications. For HIPAA, it could expose protected health information, violating compliance requirements.

Mitigation Strategies

Update 7-Zip to the latest version to patch the heap-based buffer overflow in XZ decompression. Avoid opening files or visiting websites from untrusted sources until patched.

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