Vulnerability · Published May 19, 2026 · Assigned by GitHub_M

CVE-2026-32739libheif is Vulnerable to Infinite Loop DoS via stts Sample Duration Lookup

Medium 6.5

In plain English

A medium-severity infinite loop in libheif from strukturag. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.3%top 74.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.21.2 and below, a crafted 800-byte HEIF sequence file causes an infinite loop in Box_stts::get_sample_duration(), consuming 100% CPU indefinitely with zero progress, leading to DoS. The loop has no iteration limit or timeout and is triggered during file open (parsing) - before any user interaction or image decoding. The process stays alive (no crash, no error logged), making it invisible to crash-based monitoring. This issue has been fixed in version 1.22.0.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Alpine:v3.23	libheif	1.23.0-r0	ALPINE-CVE-2026-32739
Alpine:v3.24	libheif	1.22.2-r0	ALPINE-CVE-2026-32739
Debian:12	libheif	no fix listed	DEBIAN-CVE-2026-32739
Debian:14	libheif	1.23.1-1	DEBIAN-CVE-2026-32739
Ubuntu:25.10	libheif	1.20.2-1ubuntu0.4	UBUNTU-CVE-2026-32739
Ubuntu:26.04:LTS	libheif	1.21.2-3ubuntu0.1	UBUNTU-CVE-2026-32739

Affected products (as reported)

Vendor	Product	Versions
strukturag	libheif	< 1.22.0

Weakness: CWE-835 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References

https://github.com/strukturag/libheif/security/advisories/GHSA-j9g7-q9hv-gq8c x_refsource_CONFIRM
https://github.com/strukturag/libheif/releases/tag/v1.22.0 x_refsource_MISC