CVE-2026-47251
libheif has an incomplete fix for CVE-2026-3949: integer overflow bypass in vvdec_push_data2
- State
- Published
- Severity
- 6.8 Medium
- Published
- Jul 21, 2026
- Updated
- Jul 22, 2026
- Reserved
- May 18, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.8 Medium | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N | GitHub_M |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
libheifstrukturag |
|
References
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