CVE-2026-50142: libheif is a HEIF and AVIF file format decoder and encoder

This month

HIGH 7.5REMOTE

CVE-2026-50142 is a high-severity flaw (CVSS 7.5) affecting affected software. 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. From 1.19.0 until 1.23.0, a crafted HEIF sequence accepted by heif_context_read_from_memory() with the msf1 sequence brand can cause unbounded heap allocation. In libheif/sequences/seq_boxes.cc, Box_stsz::parse() applies max_sequence_frames only to variable-size samples, so fixed-size mode accepts an attacker-controlled sample_count without a bound. In libheif/sequences/track.cc, Track::

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 49%)
CISA exploited list	No
Weakness	CWE-190, CWE-770
Published	2026-08-18
Last modified	2026-10-22

Publisher (CNA): GitHub, Inc.

Last updated 2026-10-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-08-18Published CVE record published
2026-10-22 17:09 UTCUpdated Record last modified

Exact fixes by distribution

Fedora 46 · kwin-zones · FIXED · 1.0.13-1.fc46 · FEDORA-2026-95888f332b · source

sudo dnf upgrade --advisory=FEDORA-2026-95888f332b

Fedora ELN · nginx-mod-brotli · FIXED · 1.0.0~rc-16.eln159 · FEDORA-2026-501a6a8273 · source

sudo dnf upgrade --advisory=FEDORA-2026-501a6a8273

Ubuntu 20.04 · libheif · NOT AFFECTED

Ubuntu 22.04 · libheif · NOT AFFECTED

Ubuntu 25.10 · libheif · FIXED · 1.20.2-1ubuntu0.6

sudo apt update && sudo apt install --only-upgrade libheif dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libheif)" ge "1.20.2-1ubuntu0.6" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.04 · libheif · NOT AFFECTED

Debian 12 · libheif · NO FIX YET

Debian 13 · libheif · NOT AFFECTED

Alpine 3.23 · libheif · FIXED · libheif-1.23.0-r0

apk add --upgrade libheif apk info -v libheif

Alpine 3.24 · libheif · FIXED · libheif-1.23.0-r0

apk add --upgrade libheif apk info -v libheif

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: MuhammedHussein17/libheif-cve-2026-50142 (0 stars)
Write-up: github.com/strukturag/libheif/security/advisories/GHSA-jvmp-j3cw-84mh

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-2026-50142?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-50142 being exploited?

CVE-2026-50142 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-2026-50142 affect?

CVE-2026-50142 affects affected software. Severity is high (CVSS 7.5). libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.0, a crafted HEIF sequence accepted by heif_context_read_from_memory() with the msf1 sequence brand can cause unbounded heap allocation. In libheif/sequences

How urgent is CVE-2026-50142?

Priority 44/100. High severity; Remotely exploitable, no login, no user action

References

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