CVE-2026-34378
Signed Integer Overflow in OpenEXR dataWindow Causes Crash
Publication date: 2026-04-06
Last updated on: 2026-04-07
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| openexr | openexr | From 3.4.0 (inc) to 3.4.9 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-190 | The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in OpenEXR versions from 3.4.0 to before 3.4.9. It involves a missing bounds check on the dataWindow attribute in EXR file headers. An attacker can exploit this by setting dataWindow.min.x to a large negative value, which causes a signed integer overflow in the generic_unpack() function. Specifically, OpenEXRCore calculates an enormous image width from this value, leading to a signed integer multiplication overflow. This overflow causes the process to terminate unexpectedly with a SIGILL signal triggered by Undefined Behavior Sanitizer (UBSan). The issue is fixed in version 3.4.9.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify any direct impact of this vulnerability on compliance with common standards and regulations such as GDPR or HIPAA.
How can this vulnerability impact me? :
The primary impact of this vulnerability is a denial of service condition. By exploiting the signed integer overflow, an attacker can cause the affected process to crash with a SIGILL signal. This can disrupt applications or services that use OpenEXR to process EXR image files, potentially leading to service interruptions or instability.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade OpenEXR to version 3.4.9 or later, where the signed integer overflow issue in generic_unpack() has been fixed.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability involves a signed integer overflow triggered by crafted EXR files with a negative dataWindow.min.x value. Detection involves identifying or analyzing EXR files that may exploit this condition.
To detect this vulnerability on your system, you can:
- Check the version of OpenEXR installed to ensure it is 3.4.9 or later, as versions before 3.4.9 are vulnerable.
- Scan for suspicious or crafted EXR files that contain a negative dataWindow.min.x value in their headers.
Suggested commands:
- Use a package manager or command to check the installed OpenEXR version, for example: `openexr --version` or `dpkg -l | grep openexr` on Debian-based systems.
- Use a hex editor or a custom script to inspect EXR file headers for the dataWindow.min.x attribute and check if it contains large negative values.
- Monitor application logs for crashes or SIGILL signals related to OpenEXR processing, which may indicate exploitation attempts.