Integer Overflow or Wraparound Affecting openexr package, versions <3.1.13-2ubuntu0.26.04.1~esm1


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.38% (30th percentile)

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  • Snyk IDSNYK-UBUNTU2604-OPENEXR-16234876
  • published7 May 2026
  • disclosed6 Apr 2026

Introduced: 6 Apr 2026

CVE-2026-34380  (opens in a new tab)
CWE-190  (opens in a new tab)
CWE-787  (opens in a new tab)

How to fix?

Upgrade Ubuntu:26.04 openexr to version 3.1.13-2ubuntu0.26.04.1~esm1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream openexr package and not the openexr package as distributed by Ubuntu. See How to fix? for Ubuntu:26.04 relevant fixed versions and status.

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.2.0 to before 3.2.7, 3.3.9, and 3.4.9, a signed integer overflow exists in undo_pxr24_impl() in src/lib/OpenEXRCore/internal_pxr24.c at line 377. The expression (uint64_t)(w * 3) computes w * 3 as a signed 32-bit integer before casting to uint64_t. When w is large, this multiplication constitutes undefined behavior under the C standard. On tested builds (clang/gcc without sanitizers), two's-complement wraparound commonly occurs, and for specific values of w the wrapped result is a small positive integer, which may allow the subsequent bounds check to pass incorrectly. If the check is bypassed, the decoding loop proceeds to write pixel data through dout, potentially extending far beyond the allocated output buffer. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.

CVSS Base Scores

version 3.1