CVE-2026-47251 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-47251MEDIUM

strukturag libheif — libheif has an incomplete fix for CVE-2026-3949: integer overflow bypass in vvdec_push_data2

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   L   L   N   N   A   L   N   H    6.8   .0018    7.8     —

AFFECTED
  Product  Versions    Fixed
  libheif  < 1.22.0 –  —

TIMELINE
  May 18  Reserved by GitHub_M
  Jul 21  EXPLOIT PUBLISHED — CVE-2026-47251 (strukturag libheif). Public exploit reference added.
  Jul 21  Published (CNA: GitHub_M)
  Jul 27  EXPLOIT PUBLISHED — CVE-2026-47251 (strukturag libheif). Public exploit reference added.

CWE-125, CWE-190 · CNA: GitHub_M · CVSS v4.0 · 2 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
May 18, 2026	Reserved	Reserved by GitHub_M
July 21, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-47251 (strukturag libheif). Public exploit reference added.
July 21, 2026	Published	Published (CNA: GitHub_M)
July 27, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-47251 (strukturag libheif). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
strukturag	libheif	—	< 1.22.0	—

Weaknesses

CWE-125 · CWE-190

References (2)

https://github.com/strukturag/libheif/issues/1712 [Issue Tracking]
https://github.com/strukturag/libheif/security/advisories/GHSA-p6q9-fhf2-vj9v [Exploit, Vendor Advisory]

Authoritative record: CVE-2026-47251 at cve.org

Vendors: strukturag

Weaknesses: CWE-125 · CWE-190

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-47251 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.