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Fencer Vulns
medium 6.5

CVE-2026-32738 json

libheif has a Heap OOB Read/SEGV Crash via Zero samples_per_chunk

published 2026-05-19 5 mo ago modified 2026-07-25 3 mo ago also EUVD-2026-30972 , JLSEC-2026-570

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits
0
none known

Summary

libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.21.2 and below, a crafted 792-byte HEIF sequence file with samples_per_chunk=0 in the stsc box causes an unsigned integer underflow in the Chunk constructor (m_last_sample = 0 + 0 - 1 = UINT32_MAX), mapping all samples to an empty chunk and resulting in a denial of service. When any sample is accessed, the library reads from index 0 of an empty std::vector, causing a guaranteed SEGV (null-page read). The file parses successfully without producing an error; the crash occurs on the first frame access. This issue has been fixed in version 1.22.0.

Patch / fix

  • julia libheif_jll 1.22.2000+0
  • struktur libheif 1.22.0
  • libheif Debian 14 1.23.1-1

debian advisories DEBIAN-CVE-2026-32738

  • libheif Ubuntu 25.10 1.20.2-1ubuntu0.4
  • libheif Ubuntu 26.04 LTS 1.21.2-3ubuntu0.1

ubuntu advisories UBUNTU-CVE-2026-32738

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 SLE Module for Package Hub 15 SP7, SLE Module for Desktop Applications 15 SP7 1.23.0-150700.3.15.1
  • libheif SLES for SAP applications 16.0, SLES 16.0 1.23.0-160000.1.1

suse advisories SUSE-SU-2026:2622-1SUSE-SU-2026:22153-1

  • libheif openSUSE Leap 16.0 1.23.0-160000.1.1
  • libheif openSUSE Tumbleweed 1.22.2-1.1

opensuse advisories openSUSE-SU-2026:20974-1openSUSE-SU-2026:10878-1

  • libheif Alpine 3.23 1.23.0-r0
  • libheif Alpine 3.24 1.22.2-r0

alpine advisories ALPINE-CVE-2026-32738

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2026-32738 updated cvss 6.5

libheif: libheif: Unsigned integer underflow leads to Denial of Service

  • Red Hat Enterprise Linux 10 glycin-loaders
    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
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/strukturag/libheif/security/advisories/GHSA-7f2h-cmpf-v9ww referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
julia libheif_jll
<1.22.2000+0
1.22.2000+0

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.