CVE-2026-47251 | libheif is a HEIF and AVIF file format decoder and encoder. … | CVSS 6.8 MEDIUM

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.

Metadata

CVE ID: CVE-2026-47251
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-05-18 22:54 UTC
Published: 2026-07-21 21:18 UTC
Last updated: 2026-07-21 21:18 UTC
Primary CWE: CWE-125
CWE-125: Out-of-bounds Read
Vendor / Product: strukturag / libheif
Sources: cve.org · NVD

Severity & Metrics

6.8 MEDIUM CVSS 4.0

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

Affected products (1)

Vendor	Product	Platform	Versions
strukturag	libheif	—	< 1.22.0

Weakness (CWE)

CWE	Source	Description
CWE-125	cna	CWE-125: Out-of-bounds Read
CWE-190	cna	CWE-190: Integer Overflow or Wraparound

CVSS scores (1)

Score	Severity	Version	Source	Vector
6.8	MEDIUM	4.0	cna	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

References (2)

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