Out-of-bounds Read in Academysoftwarefoundation Openimageio
CVE-2026-59956
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (10.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 10.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Academysoftwarefoundation Openimageio — versions < 3.0.20.0, >= 3.1.0.0, < 3.1.15.0, >= 3.2.0.0-dev, < 3.2.0.3-beta1
- Openimageio — versions 3.2.0.0, 3.2.0.2
Weakness classification (CWE)
References
- github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-hjfv-… (Exploit, Vendor Advisory)
- github.com/AcademySoftwareFoundation/OpenImageIO/pull/5251 (Patch, Issue Tracking)
- github.com/AcademySoftwareFoundation/OpenImageIO/commit/f01bd16764b2a06f372899e… (Patch)
- github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.0.20.0 (Release Notes)
- github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.1.15.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-59956?
- CVE-2026-59956 is a medium-severity vulnerability in Academysoftwarefoundation Openimageio, classified under Out-of-bounds Read. CVSS score: 6.1/10. Published 2026-09-18.
- How severe is CVE-2026-59956?
- Medium severity. CVSS v3 base score is 6.1 out of 10.