CVE-2026-59956: Openimageio

Medium severity, CVSS 6.1. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Openimageio Openimageio: before 3.0.20.0 (fixed in 3.0.20.0); from 3.1.0.0, up to and including 3.1.15.0; version 3.2.0.0 only; version 3.2.0.2 only

Published 2026-09-18. Last modified 2026-09-29.