CVE-2026-66759
A flaw was found in the file-icns plugin in GIMP. When applying a decompressed mask during ICNS image processing, the plugin reads from the mask data buffer without verifying if the cursor exceeds the allocated resource size. If a crafted file contains a truncated mask resource, the icns_decompress function continues reading past the bounds of the buffer. This out-of-bounds read vulnerability results in information disclosure of heap contents, where memory contents are leaked as alpha channel pixel values, or a crash leading to a denial of service if unmapped memory is accessed.
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 3.1 : 7.1 HIGH
Vector: AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.