CVE-2026-26981: Openexr

Medium severity, CVSS 6.5. EPSS: 0.5% chance of exploitation in the next 30 days.

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. In versions 3.3.0 through 3.3.6 and 3.4.0 through 3.4.4, a heap-buffer-overflow (OOB read) occurs in the `istream_nonparallel_read` function in `ImfContextInit.cpp` when parsing a malformed EXR file through a memory-mapped `IStream`. A signed integer subtraction produces a negative value that is implicitly converted to `size_t`, resulting in a massive length being passed to `memcpy`. Versions 3.3.7 and 3.4.5 contain a patch.

Affected products

• Openexr Openexr: from 3.3.0, before 3.3.7 (fixed in 3.3.7); from 3.4.0, before 3.4.5 (fixed in 3.4.5)

Published 2026-02-24. Last modified 2026-06-17.