CVE-2026-27622: academysoftwarefoundation openexr Out-of-bounds Write

Vulnerability summary

CVE-2026-27622 is a high (CVSS 8.4) Out-of-bounds Write vulnerability in academysoftwarefoundation openexr. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 12.5% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 03-03-2026
   PublishedVulnerability first disclosed.
2. 09-09-2026
   Last modifiedVulnerability information updated.

Description

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. In CompositeDeepScanLine::readPixels, per-pixel totals are accumulated in vector<unsigned int> total_sizes for attacker-controlled large counts across many parts, total_sizes[ptr] wraps modulo 2^32. overall_sample_count is then derived from wrapped totals and used in samples[channel].resize(overall_sample_count). Decode pointer setup/consumption proceeds with true sample counts, and write operations in core unpack (generic_unpack_deep_pointers) overrun the undersized composite sample buffer. This vulnerability is fixed in v3.2.6, v3.3.8, and v3.4.6.

• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.