CVE-2026-47251

Published Jul 21, 2026

Last updated 3 months ago

Overview

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.
Source
security-advisories@github.com
NVD status
Analyzed
Products
libheif

Risk scores

CVSS 4.0

Type
Secondary
Base score
6.8
Impact score
-
Exploitability score
-
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity
MEDIUM

CVSS 3.1

Type
Primary
Base score
6.1
Impact score
4.2
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
Severity
MEDIUM

Weaknesses

security-advisories@github.com
CWE-125

Social media

Hype score
Not currently trending

Configurations