Buffer overflow in Academysoftwarefoundation Openexr

CVE-2026-55059

OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. Versions prior to 3.2.10, 3.3.12 and 3.4.13 contain a heap out-of-bounds write in Imf_4_0::SampleCountChannel::set(int r, unsigned int newNumSamples[]). The row-based sample-count setter computes the target Y coordinate with dataWindow.min.x instead of dataWindow.min.y. For a valid deep image data window where min.x != min.y, a valid row index can be translated into an invalid Y coordinate, causing writes before the allocated _numSamples buffer. The vulnerability is reachable through the public OpenEXRUtil DeepImage API and can lead to heap corruption and process crashes. This issue has been fixed in versions 3.2.10, 3.3.12 and 3.4.13.

Vulnerability class: Buffer Overflow

EPSS: 0.001 (1.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-55059?
CVE-2026-55059 is a medium-severity vulnerability in Academysoftwarefoundation Openexr, classified under Out-of-bounds Write. CVSS score: 6.1/10. Published 2026-08-25.
How severe is CVE-2026-55059?
Medium severity. CVSS v3 base score is 6.1 out of 10.