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Fencer Vulns
high 7.1

CVE-2026-32741 json

libheif has a heap buffer overflow in decode_mask_image()

published 2026-05-19 5 mo ago modified 2026-07-24 3 mo ago also EUVD-2026-30982

cvss
7.1
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 28%
public exploits
0
none known

Summary

libheif is a HEIF and AVIF file format decoder and encoder. Versions 1.21.2 and below contain a heap buffer overflow in MaskImageCodec::decode_mask_image(). When decoding a HEIF file containing a mask image (mski), the function copies the full iloc extent data into a pixel buffer using memcpy(dst, data.data(), data.size()). The copy length data.size() is determined by the iloc extent in the file (attacker-controlled), while the destination buffer is sized based on the declared image dimensions. Because no upper-bound check exists on the data length, a crafted file whose iloc extent exceeds the pixel buffer allocation overflows the heap. The vulnerable single-memcpy branch is reached when the mskC property specifies bits_per_pixel = 8 and the ispe property declares an even width ≥ 64 (so that stride == width), with no changes to default security limits or external codec plugins required. This issue has been fixed in version 1.22.0.

Patch / fix

  • struktur libheif 1.22.0
  • libheif Debian 13 1.19.8-1+deb13u1
  • libheif Debian 14 1.23.1-1

debian advisories DEBIAN-CVE-2026-32741

  • libheif Ubuntu 24.04 LTS 1.17.6-1ubuntu4.4
  • libheif Ubuntu 25.10 1.20.2-1ubuntu0.4
  • libheif Ubuntu 26.04 LTS 1.21.2-3ubuntu0.1

ubuntu advisories UBUNTU-CVE-2026-32741

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

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-2026-32741 updated cvss 7.1

libheif: libheif: Heap buffer overflow vulnerability in image decoding

  • 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

0.34% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/strukturag/libheif/security/advisories/GHSA-j3w5-7whq-p37q referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
CISA ADP 3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H

Affected products

  • strukturag libheif
  • Red Hat Red Hat Enterprise Linux 10

Classification

Weakness
  • CWE-122 Heap-based Buffer Overflow
  • CWE-120 Buffer Copy without Checking Size of Input

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.