Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Struktur | Libheif | < 1.22.0 |
Related Weaknesses (CWE)
References
- https://github.com/strukturag/libheif/issues/1712Issue Tracking
- https://github.com/strukturag/libheif/security/advisories/GHSA-p6q9-fhf2-vj9vExploitVendor Advisory
- https://github.com/strukturag/libheif/issues/1712Issue Tracking
- https://github.com/strukturag/libheif/security/advisories/GHSA-p6q9-fhf2-vj9vExploitVendor Advisory
FAQ
What is CVE-2026-47251?
CVE-2026-47251 is a vulnerability with a CVSS score of 6.1 (MEDIUM). 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 ...
How severe is CVE-2026-47251?
CVE-2026-47251 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-47251?
Check the references section above for vendor advisories and patch information. Affected products include: Struktur Libheif.