CVE-2026-34380

Summary

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.

Affected Software

VendorProductVersion RangeStatus
AcademySoftwareFoundationopenexr>= 3.2.0, < 3.2.7affected
AcademySoftwareFoundationopenexr>= 3.3.0, < 3.3.9affected
AcademySoftwareFoundationopenexr>= 3.4.0, < 3.4.9affected

Weaknesses

  • CWE-190: CWE-190: Integer Overflow or Wraparound
  • CWE-787: CWE-787: Out-of-bounds Write

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

References