CVE-2026-67549 OpenImageIO: TIFF 1-bit CMYK bit conversion heap out-of-bounds write
A heap out-of-bounds write in OpenImageIO allows attackers to cause memory corruption and potentially execute code via crafted TIFF files.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-67549?
CVE-2026-67549 is a high-severity memory corruption vulnerability in Openimageio Openimageio, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Which versions are affected by CVE-2026-67549?
It affects 1 product.
Products include Openimageio Openimageio.
How do I fix CVE-2026-67549?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-67549 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67549 exists.
Other vulnerabilities in Openimageio Openimageio
Sources
Also known as GHSA-3wxw-rqhw-j2w4, UBUNTU-CVE-2026-67549.