Out-of-bounds write in libheif - #VU135517
Published: June 26, 2026
Vulnerability identifier: #VU135517
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: N/A
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: struktur AG
Affected software:
libheif
libheif
Detailed vulnerability description
The vulnerability allows a remote attacker to cause memory corruption.
The vulnerability exists due to out-of-bounds write in unc_encoder_component_interleave::encode_tile when re-encoding a decoded image with mismatched primary and auxiliary alpha plane dimensions. A remote attacker can trick the victim into opening a specially crafted HEIF sequence file and re-encoding the decoded frame to cause memory corruption.
User interaction is required to open a crafted file, and exploitation occurs through a decode and re-encode workflow using the public APIs.
Remediation
Install security update from vendor's website.