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 trend (30 days)EPSS over the last 30 days for CVE-2026-59956: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

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.