6.8
MEDIUM CVSS 4.0
CVE-2026-47251
libheif has an incomplete fix for CVE-2026-3949: integer overflow bypass in vvdec_push_data2
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.

INFO

Published Date :

July 21, 2026, 10:17 p.m.

Last Modified :

July 22, 2026, 8:38 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-47251 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Struktur libheif
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 4.0 MEDIUM [email protected]
Solution
Update libheif to version 1.22.0 to fix an out-of-bounds heap read vulnerability.
  • Update libheif to version 1.22.0.
  • Ensure security checks are tested thoroughly.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-47251 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-47251 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-47251 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-47251 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 22, 2026

    Action Type Old Value New Value
    Added Reference https://github.com/strukturag/libheif/issues/1712
    Added Reference https://github.com/strukturag/libheif/security/advisories/GHSA-p6q9-fhf2-vj9v
    Added SSVC {'id': 'CVE-2026-47251', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-22T13:38:27.784638Z'}
  • New CVE Received by [email protected]

    Jul. 21, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'strukturag', 'product': 'libheif', 'versions': [{'status': 'affected', 'version': '< 1.22.0'}]}]
    Added 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.
    Added CVSS V4.0 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
    Added CWE CWE-125
    Added CWE CWE-190
    Added Reference https://github.com/strukturag/libheif/issues/1712
    Added Reference https://github.com/strukturag/libheif/security/advisories/GHSA-p6q9-fhf2-vj9v
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.