Medium severity · published Sep 18, 2026
CVE-2026-59956
OpenImageIO: Heap-buffer-overread in IffInput::readimg() when ZBUFFER flag is set
6.1
CVSS
0.2%
EPSS
No
On KEV
Description
OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.0.20.0, 3.1.15.0, and 3.2.0.3-beta1, An uncompressed 16-bit iff image with a z-buffer makes iffinput::readimg() allocate a temporary scanline from m_header.rgba_count but copy from it using m_header.pixel_bytes(), whose stride also includes z-buffer bytes. the oversized memcpy reads beyond the temporary heap buffer and copies adjacent memory into the output image, resulting in a crash or disclosure of adjacent heap data. The affected implementation is identified by src/iff.imageio/iffinput.cpp, IffInput::readimg(), m_header.rgba_count, and m_header.pixel_bytes(), which define the relevant source path, functions, state, and trigger. This issue is fixed in versions 3.0.20.0, 3.1.15.0, and 3.2.0.3-beta1.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 10% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
OpenImageIO · AcademySoftwareFoundation
< 3.0.20.0; >= 3.1.0.0, < 3.1.15.0; >= 3.2.0.0-dev, < 3.2.0.3-beta1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-59956
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-59956
Patch
https://github.com/AcademySoftwareFoundation/OpenImageIO/commit/f01bd16764b2a06f372899e3e302280a7f9c8c02
Issue Tracking
https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/5251
Release Notes
https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.0.20.0
Release Notes
https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.1.15.0
Exploit
https://github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-hjfv-gvxc-qgvh
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