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Fencer Vulns
medium 5.3

CVE-2026-62291 json

libheif: Heap out of bounds write in libheif uncompressed encoder when writing images with mismatched auxiliary alpha dimensions

published 2026-08-18 2 mo ago modified 2026-10-22 18 d ago also EUVD-2026-62190

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
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 image sequence with a 2x2 primary plane and a 256x256 auxiliary alpha plane can cause attacker-controlled heap corruption during a normal decode and re-encode workflow. Track_Visual::decode_next_image_sample() calls transfer_channel_from_image_as() without checking that the auxiliary alpha dimensions match the main frame. The resulting inconsistent image reaches heif_track_decode_next_image() and then heif_context_encode_image(). In unc_encoder::encode(), unc_encoder_component_interleave::encode_tile() sizes its buffer with compute_tile_data_size_bytes() using the primary dimensions but copies each component using its actual plane dimensions. The oversized alpha plane is therefore copied beyond the allocation, causing an out-of-bounds write; the inverse size mismatch can also produce an out-of-bounds read. This issue is fixed in version 1.23.1.

Patch / fix

  • struktur libheif 1.23.1
  • libheif Debian 14 1.23.1-1

debian advisories DEBIAN-CVE-2026-62291

  • libheif Ubuntu 24.04 LTS 1.17.6-1ubuntu4.8
  • libheif Ubuntu 26.04 LTS 1.21.2-3ubuntu0.5

ubuntu advisories UBUNTU-CVE-2026-62291

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-2026-62291 updated cvss 5.3

libheif: libheif: Arbitrary code execution via heap corruption in image processing

  • 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
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/strukturag/libheif/security/advisories/GHSA-xpw3-9rhw-482x referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/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.

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