Integer Overflow or Wraparound Affecting openexr package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.06% (19th percentile)

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  • Snyk IDSNYK-RHEL9-OPENEXR-16122391
  • published22 Apr 2026
  • disclosed21 Apr 2026

Introduced: 21 Apr 2026

CVE-2026-39886  (opens in a new tab)
CWE-190  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:9 openexr.

NVD Description

Note: Versions mentioned in the description apply only to the upstream openexr package and not the openexr package as distributed by RHEL. See How to fix? for RHEL:9 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. Versions 3.4.0 through 3.4.9 have a signed integer overflow vulnerability in OpenEXR's HTJ2K (High-Throughput JPEG 2000) decompression path. The ht_undo_impl() function in src/lib/OpenEXRCore/internal_ht.cpp accumulates a bytes-per-line value (bpl) using a 32-bit signed integer with no overflow guard. A crafted EXR file with 16,385 FLOAT channels at the HTJ2K maximum width of 32,767 causes bpl to overflow INT_MAX, producing undefined behavior confirmed by UBSan. On an allocator-permissive host where the required ~64 GB allocation succeeds, the wrapped negative bpl value would subsequently be used as a per-scanline pointer advance, which would produce a heap out-of-bounds write. On a memory-constrained host, the allocation fails before ht_undo_impl() is entered. This is the second distinct integer overflow in ht_undo_impl(). CVE-2026-34545 addressed a different overflow in the same function — the int16_t p pixel-loop counter at line ~302 that overflows when iterating over channels whose width exceeds 32,767. The CVE-2026-34545 fix did not touch the int bpl accumulator at line 211, which is the subject of this advisory. The bpl accumulator was also not addressed by any of the 8 advisories in the 2026-04-05 v3.4.9 release batch. This finding is structurally identical to CVE-2026-34588 (PIZ wcount*nx overflow in internal_piz.c) and should be remediated with the same pattern. The CVE-2026-34588 fix did not touch internal_ht.cpp. Version 3.4.10 contains a remediation that addresses the vulnerability in internal_ht.cpp.

CVSS Base Scores

version 3.1