AcademySoftwareFoundation OpenEXR up to 3.2.6/3.3.8/3.4.8 EXR File Parser internal_dwa_decoder.h LossyDctDecoder_execute type conversion

Summaryinfo

A vulnerability identified as problematic has been detected in AcademySoftwareFoundation OpenEXR up to 3.2.6/3.3.8/3.4.8. Impacted is the function LossyDctDecoder_execute in the library src/lib/OpenEXRCore/internal_dwa_decoder.h of the component EXR File Parser. This manipulation causes type conversion. This vulnerability is registered as CVE-2026-34379. Remote exploitation of the attack is possible. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in AcademySoftwareFoundation OpenEXR up to 3.2.6/3.3.8/3.4.8. It has been declared as problematic. Affected by this vulnerability is the function LossyDctDecoder_execute in the library src/lib/OpenEXRCore/internal_dwa_decoder.h of the component EXR File Parser. The manipulation with an unknown input leads to a type conversion vulnerability. The CWE definition for the vulnerability is CWE-704. The product does not correctly convert an object, resource, or structure from one type to a different type. As an impact it is known to affect integrity, and availability. The summary by CVE is:

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.2.0 to before 3.2.7, 3.3.9, and 3.4.9, a misaligned memory write vulnerability exists in LossyDctDecoder_execute() in src/lib/OpenEXRCore/internal_dwa_decoder.h:749. When decoding a DWA or DWAB-compressed EXR file containing a FLOAT-type channel, the decoder performs an in-place HALF→FLOAT conversion by casting an unaligned uint8_t * row pointer to float * and writing through it. Because the row buffer may not be 4-byte aligned, this constitutes undefined behavior under the C standard and crashes immediately on architectures that enforce alignment (ARM, RISC-V, etc.). On x86 it is silently tolerated at runtime but remains exploitable via compiler optimizations that assume aligned access. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-34379 since 03/27/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 305083 (Linux Distros Unpatched Vulnerability : CVE-2026-34379), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.2.7, 3.3.9 or 3.4.9 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (305083). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• AcademySoftwareFoundation

Name

• OpenEXR

Version

• 3.2.0
• 3.2.1
• 3.2.2
• 3.2.3
• 3.2.4
• 3.2.5
• 3.2.6
• 3.3.0
• 3.3.1
• 3.3.2
• 3.3.3
• 3.3.4
• 3.3.5
• 3.3.6
• 3.3.7
• 3.3.8
• 3.4.0
• 3.4.1
• 3.4.2
• 3.4.3
• 3.4.4
• 3.4.5
• 3.4.6
• 3.4.7
• 3.4.8

License

• open-source

Website

• Product: https://github.com/AcademySoftwareFoundation/openexr/

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