CVE-2026-68516 OpenEXR: HTJ2K SIZ image-offset gap stack buffer overflow
A crafted HTJ2K-compressed EXR file can cause a stack buffer overflow in OpenEXR, leading to a denial of service during image decoding.
- 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-2026-68516?
CVE-2026-68516 is a medium-severity memory corruption vulnerability in AcademySoftwareFoundation openexr, published on 24 Aug 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
OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. From version 3.4.0 through 3.4.13, a crafted HTJ2K-compressed EXR can crash OpenEXR during normal decode. An HTJ2K-compressed EXR whose JPEG 2000 SIZ fields place the first tile outside the visible image can reach invalid tile and codeblock geometry in the vendored OpenJPH AVX2 decoder, causing a stack out-of-bounds write and denial of service. OpenEXR's HTJ2K path validates the decoded codestream dimensions against the EXR chunk size, but it does not reject SIZ image-offset/tile-grid geometry where the first tile does not intersect the image. This issue is fixed in version 3.4.14.
Which versions are affected by CVE-2026-68516?
How do I fix CVE-2026-68516?
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-2026-68516 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-68516 exists.
Sources
Also known as BELL-CVE-2026-68516, DEBIAN-CVE-2026-68516, GHSA-fw66-6xph-56jm, MINI-7x59-6w4j-44wf, UBUNTU-CVE-2026-68516.