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.
History

Tue, 24 Feb 2026 03:00:00 +0000

Type Values Removed Values Added
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.
Title OpenEXR has heap-buffer-overflow via signed integer underflow in ImfContextInit.cpp
Weaknesses CWE-195
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-24T02:26:16.659Z

Reserved: 2026-02-17T01:41:24.605Z

Link: CVE-2026-26981

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-02-24T03:16:01.890

Modified: 2026-02-24T03:16:01.890

Link: CVE-2026-26981

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.