Bug 2538836 (CVE-2026-67549)

Summary: CVE-2026-67549 OpenImageIO: OpenImageIO: Memory corruption when processing crafted TIFF images
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in OpenImageIO. A remote attacker could exploit this vulnerability by tricking a user into processing a specially crafted 1-bit CMYK TIFF image. The `tiffinput::bit_convert()` function incorrectly writes 8-bit output into a smaller buffer allocated for 1-bit data, causing a heap out-of-bounds write. This memory corruption could lead to a denial of service or potentially arbitrary code execution.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2539207, 2539209, 2539210    
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Description OSIDB Bzimport 2026-09-22 20:50:49 UTC 
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.