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Fencer Vulns
medium 4.3

CVE-2026-62377 json

libheif: Reachable assertion in HeifContext::get_track() aborts on a valid-but-empty HEIF sequence file (context.cc:2110)

published 2026-08-18 2 mo ago modified 2026-10-22 17 d ago also EUVD-2026-62191

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits
0
none known

Summary

libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.0 and earlier, a crafted HEIF sequence accepted by heif_context_read_from_memory() can leave the context with no registered sequence tracks and crash when heif_context_get_track(ctx, 0) is called. HeifContext::get_track() in libheif/context.cc executes assert(has_sequence()) before its normal error handling, so assert-enabled builds abort instead of allowing the public wrapper in libheif/api/libheif/heif_sequences.cc to return null. In release builds, removing the assertion lets the track_id zero path dereference m_tracks.begin()->second on an empty map, which is undefined behavior and typically crashes. The issue is reachable through documented public APIs after parsing attacker-controlled bytes. This issue is fixed in version 1.23.1.

Patch / fix

  • libheif Debian 14 1.23.1-1

debian advisories DEBIAN-CVE-2026-62377

  • libheif Ubuntu 26.04 LTS 1.21.2-3ubuntu0.5

ubuntu advisories UBUNTU-CVE-2026-62377

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libheif SLES for SAP applications 16.0, SLES 16.0 1.23.1-160000.1.1
  • libheif SLE Module for Package Hub 15 SP7, SLE Module for Desktop Applications 15 SP7 1.23.1-150700.3.18.1

suse advisories SUSE-SU-2026:23320-1SUSE-SU-2026:3597-1

  • libheif openSUSE Leap 16.0 1.23.1-160000.1.1
  • libheif openSUSE Tumbleweed 1.23.1-1.1

opensuse advisories openSUSE-SU-2026:21644-1openSUSE-SU-2026:11416-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-62377 updated cvss 6.5

libheif: libheif: Denial of Service via crafted HEIF sequence

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

Affected products

  • strukturag libheif

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.