CVE-2026-26981
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`.
Does this matter?
Lower severity and a low EPSS score (0.52%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- EPSS
- 0.52% probability · 43th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-195
- Affected
- openexr/openexr
- Source
- security-advisories@github.com
References
- https://github.com/AcademySoftwareFoundation/openexr/commit/6bb2ddf1068573d073edf81270a015b38cc05cefPatch
- https://github.com/AcademySoftwareFoundation/openexr/commit/d2be382758adc3e9ab83a3de35138ec28d93ebd8Patch
- https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-q6vj-wxvf-5m8cExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.