CVE-2026-55371 OpenEXR: OpenEXRCore exr_attr_set_bytes() accepts NULL type_hint with positive hint_length
A NULL pointer dereference in OpenEXRCore allows attackers to cause a denial of service via crafted image attributes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55371?
CVE-2026-55371 is a medium-severity vulnerability in AcademySoftwareFoundation openexr, published on 25 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
OpenEXR is the reference implementation and specification for the EXR high-dynamic-range image file format, widely used in the motion picture industry. Versions 3.4.0 through 3.4.12 contain a NULL pointer dereference in the OpenEXRCore function exr_attr_set_bytes(). The public setter validates the top-level exr_attr_bytes_t value pointer but does not verify that the nested type_hint pointer is non-NULL when hint_length is greater than zero. When a caller supplies a positive hint_length together with a NULL type_hint, exr_attr_bytes_create() allocates a destination type-hint buffer and then copies from the NULL source pointer, causing a deterministic crash. The flaw is reachable through the public OpenEXRCore C API and results in a denial of service. The issue is fixed in version 3.4.13.
Which versions are affected by CVE-2026-55371?
How do I fix CVE-2026-55371?
Upgrade to a fixed version.
Is CVE-2026-55371 being exploited?
There is no known exploitation of CVE-2026-55371 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-55371, DEBIAN-CVE-2026-55371, ECHO-ebdc-b3e5-e9c6, GHSA-xx72-f24p-cf6r, MINI-h7m9-8h23-7c39, UBUNTU-CVE-2026-55371.