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Fencer Vulns
high 7.5

CVE-2026-84446 json

libheif: Sequence decode timing-table initialization allows non-terminating loops and unbounded memory, bypassing max_sequence_frames

published 2026-09-18 52 d ago modified 2026-09-21 48 d ago also EUVD-2026-83017

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.23.2, crafted HEIF sequence timing and edit-list data can make Track::init_sample_timing_table() compute a logical m_num_output_samples value that exceeds the uint32_t counters used by Track_Visual::decode_next_image_sample() and Track::get_next_sample_raw_data(). The resulting comparison can never reach the oversized output count, causing non-terminating decode or raw-sample loops and bypassing max_sequence_frames. The same sequence path repeatedly calls Box_stts::get_sample_duration() and allocates Chunk::m_sample_ranges and Track::m_presentation_timeline outside MemoryHandle accounting, allowing severe CPU and memory exhaustion from a small file. 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-2026-84446

  • libheif Ubuntu 26.04 LTS 1.21.2-3ubuntu0.6

ubuntu advisories UBUNTU-CVE-2026-84446

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-2026-84446 updated cvss 7.5

libheif: libheif: Denial of Service via crafted HEIF sequence timing data

  • 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
yes
Technical impact
partial
Assessed
51 d ago

Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • strukturag libheif

Classification

Weakness
  • CWE-835 Loop with Unreachable Exit Condition

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.