CVE-2026-47251: libheif is a HEIF and AVIF file format decoder and encoder

Q: How do I fix CVE-2026-47251?

libheif: upgrade to 1.22.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-47251 being exploited?

CVE-2026-47251 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-47251 affect?

CVE-2026-47251 affects libheif. Severity is medium (CVSS 6.1). 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

Q: How urgent is CVE-2026-47251?

Priority 28/100. Public exploit reference

Routine

MEDIUM 6.1UPGRADE

CVE-2026-47251 is a medium-severity flaw (CVSS 6.1) affecting libheif. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 95%)
CISA exploited list	No
Weakness	CWE-125, CWE-190
Published	2026-07-21
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: struktur

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-21 22:17 UTCPublished CVE record published
2026-10-24 19:10 UTCUpdated Record last modified

struktur libheif UPGRADE

Affected: < 1.22.0

Fixed in: 1.22.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy libheif || rpm -q libheif || libheif --version

2. UPGRADE to 1.22.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade libheif

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade libheif

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-47251?

libheif: upgrade to 1.22.0. Exact commands for each OS are on this page.

Is CVE-2026-47251 being exploited?

CVE-2026-47251 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-47251 affect?

CVE-2026-47251 affects libheif. Severity is medium (CVSS 6.1). 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

How urgent is CVE-2026-47251?

Priority 28/100. Public exploit reference

Related CVEs

CVE-2026-47247 HIGH 7.5 UPGRADE libheif is a HEIF and AVIF file format decoder and encoder
CVE-2026-47178 MEDIUM 6.1 UPGRADE libheif is a HEIF and AVIF file format decoder and encoder
CVE-2026-47254 MEDIUM 6.1 UPGRADE libheif is a HEIF and AVIF file format decoder and encoder
CVE-2026-47709 MEDIUM 5.5 UPGRADE libheif is a HEIF and AVIF file format decoder and encoder
CVE-2026-47714 MEDIUM 6.1 UPGRADE libheif is a HEIF and AVIF file format decoder and encoder

References

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