CVE-2026-65979 OpenEXR: Out-of-bounds read in HTJ2K decoder from unvalidated chunk header length (PLEN)
An attacker can cause an out-of-bounds read in the OpenEXR HTJ2K decoder by providing a crafted image file, leading to potential crashes or data exposure.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-65979?
CVE-2026-65979 is a medium-severity memory corruption vulnerability in AcademySoftwareFoundation openexr, published on 25 Aug 2026. It can only be exploited from the same machine or local network, 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 3.4.12, the HTJ2K decoder parses a header-length field (PLEN) from a chunk's compressed data but never checks that this value fits within the available buffer before using it. When decoding, it advances the codestream pointer by the attacker-supplied header size and passes the resulting offset and remaining length to the OpenJPH memory-input path, so a crafted value pushes the pointer past the end of the buffer and causes an out-of-bounds read. Because this field comes straight from attacker-controlled EXR chunk data, the flaw is reachable during normal decoding of an untrusted file. This issue is fixed in version 3.4.13.
Which versions are affected by CVE-2026-65979?
How do I fix CVE-2026-65979?
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-2026-65979 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-65979 exists.
Sources
Also known as BELL-CVE-2026-65979, DEBIAN-CVE-2026-65979, GHSA-3j9c-j7c9-x293, MINI-q3x4-vw4v-7xj6, UBUNTU-CVE-2026-65979.