Access of Uninitialized Pointer in libheif - #VU158749
Published: November 3, 2026
Vulnerability identifier: #VU158749
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-824
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to failure to initialize the output image handle in libheif's heif_context_encode_thumbnail() function when encoding an image whose dimensions fit within the requested thumbnail bounding box. A remote attacker can supply such an image to a service that generates thumbnails during encoding to trigger access to an uninitialized or stale pointer, potentially causing a use-after-free, double free, invalid free, or process crash.
Affected software
libheif
Remediation
Install security update from vendor's website.
libheif - update to 1.23.7