What’s Vulnerable › Vulnerabilities

CVE-2026-26981: OpenEXR has heap-buffer-overflow via signed integer underflow in ImfContextInit.cpp

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-02-24 · updated 2026-06-17
• Weakness: CWE-195

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.

Affected products

• AcademySoftwareFoundation openexr: from 3.3.0 before 3.3.7; from 3.4.0 before 3.4.5 — fixed in 3.3.7, 3.4.5

How to fix

Upgrade to a fixed version: AcademySoftwareFoundation openexr 3.3.7, 3.4.5. Check the vendor advisory for mitigations.

References

• https://github.com/AcademySoftwareFoundation/openexr/commit/6bb2ddf1068573d073edf81270a015b38cc05cef
• https://github.com/AcademySoftwareFoundation/openexr/commit/d2be382758adc3e9ab83a3de35138ec28d93ebd8
• https://github.com/AcademySoftwareFoundation/openexr/security/advisories/GHSA-q6vj-wxvf-5m8c

Get alerted when CVE-2026-26981 or the next vulnerability affects your stack