CVE-2026-47251

libheif is a HEIF and AVIF file format decoder and encoder. The fix for CVE-2026-3949 (commit `b97c8b5`, PR #1712) introduced an integer overflow in the very security check it added. The check itself can be bypassed, allowing a crafted HEIF file with a VVC track to trigger the same out-of-bounds heap read that CVE-2026-3949 was meant to prevent. This is a separate, currently-unpatched vulnerability. Issue #1712 was closed as fixed without testing the edge case where `size` is near `UINT32_MAX`. Version 1.22.0 patches the issue.

Score

CVSS 4.0 6.8 Medium

Status

Analyzed - security-advisories@github.com

Published

2026-07-21

Last modified

2026-10-24

Weaknesses

CWE-125, CWE-190

Affected products

• Libheif (Struktur)
• Libheif (Strukturag)

References

• https://github.com/strukturag/libheif/security/advisories/GHSA-p6q9-fhf2-vj9v
• https://github.com/strukturag/libheif/issues/1712