libheif: Heap out of bounds write in libheif uncompressed encoder when writing images with mismatched auxiliary alpha dimensions
libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.0 and earlier, a crafted image sequence with a 2x2 primary plane and a 256x256 auxiliary alpha plane can cause attacker-controlled heap corruption during a normal decode and re-encode workflow. Track_Visual::decode_next_image_sample() calls transfer_ch…
Severity medium: primary CNA CVSS 5.3 v3.1 (worst CNA-provided scenario) Not listed in this KEV snapshot. Forecast present in this snapshot.
Published 2026-08-18T21:21:32.182Z. Updated 2026-08-21T19:11:12.114Z.