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Fencer Vulns
medium 4.0

CVE-2026-84448 json

libheif: Heap out-of-bounds read in libheif inline-mask region API (heif_region_item_add_region_inline_mask_data / heif_region_get_mask_image)

published 2026-09-18 52 d ago modified 2026-09-24 45 d ago also EUVD-2026-83015

cvss
4.0
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. Prior to 1.23.2, the public heif_region_item_add_region_inline_mask_data() function in libheif/api/libheif/heif_regions.cc accepts mask_data_len without verifying that it equals the byte count required by width and height. A later heif_region_get_mask_image() call derives the read length from the region geometry, so an undersized stored buffer causes heif_region_get_inline_mask_image() to read beyond the heap allocation and copy adjacent bytes into the returned monochrome mask image. This can disclose heap data or crash an application that constructs region metadata through the writer API, while the file-parsing path is not affected because it validates the canonical mask size. This issue is fixed in version 1.23.2.

Patch / fix

  • struktur libheif 1.23.2
  • libheif Debian 13 1.23.4-1~deb13u1
  • libheif Debian 14 1.23.2-1

debian advisories DEBIAN-CVE-2026-84448

  • libheif Ubuntu 24.04 LTS 1.17.6-1ubuntu4.9
  • libheif Ubuntu 26.04 LTS 1.21.2-3ubuntu0.6

ubuntu advisories UBUNTU-CVE-2026-84448

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 1.23.4-150700.3.21.1

suse advisories SUSE-SU-2026:4276-1

  • libheif openSUSE Leap 16.0 1.23.4-160000.1.1
  • libheif openSUSE Tumbleweed 1.23.4-1.1

opensuse advisories openSUSE-SU-2026:21889-1openSUSE-SU-2026:11719-1

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-2026-84448 updated cvss 4.0

libheif: libheif: Information disclosure and denial of service due to heap out-of-bounds read

  • 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
45 d 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-p58j-h3vm-3fp5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.0 CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

Affected products

  • strukturag libheif

Classification

Weakness
  • CWE-125 Out-of-bounds Read
  • CWE-131 Incorrect Calculation of Buffer Size

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.