Medium severity · published May 19, 2026
CVE-2026-32739
libheif is Vulnerable to Infinite Loop DoS via stts Sample Duration Lookup
6.5
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
libheif · strukturag
< 1.22.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-32739
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-32739
Release Notes
https://github.com/strukturag/libheif/releases/tag/v1.22.0
Exploit
https://github.com/strukturag/libheif/security/advisories/GHSA-j9g7-q9hv-gq8c
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