Excessive Iteration in libheif - #VU158751
Published: November 3, 2026
Vulnerability identifier: #VU158751
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-834
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service through CPU exhaustion in applications that decode untrusted HEIF images.
The vulnerability exists due to excessive iteration in libheif's ImageItem::decode_image() when processing repeated image transformation associations. A remote attacker can supply a crafted HEIF file containing repeated irot, imir, or clap associations to trigger repeated full-image transformations and exhaust a decoding worker's CPU resources.
Affected software
libheif
Remediation
Install security update from vendor's website.
libheif - update to 1.23.7