CVE-2026-67549

OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.1.16.0, A crafted 1-bit contiguous cmyk tiff is exposed through a native uint1 imagespec, so callers allocate a bit-packed buffer. tiffinput::read_native_scanline_locked() nevertheless invokes tiffinput::bit_convert() with 8-bit output and writes one expanded byte per value into that smaller buffer, resulting in a heap out-of-bounds write and memory corruption. The affected implementation is identified by src/tiff.imageio/tiffinput.cpp, TIFFInput::bit_convert(), TIFFInput::read_native_scanline_locked(), PHOTOMETRIC_SEPARATED, 1-bit CMYK, and native uint1 ImageSpec, which define the relevant source path, functions, state, and trigger. This issue is fixed in 3.1.16.0.

• https://github.com/AcademySoftwareFoundation/OpenImageIO/commit/6e9b86ee4cce8fd7bed6cfb101a266d8f8a296d4Patch
• https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/5296Issue Tracking
• https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.1.16.0Release Notes
• https://github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-3wxw-rqhw-j2w4Exploit
• https://github.com/user-attachments/files/29615314/poc.zipExploit