CVE-2025-68431: Struktur Libheif

High severity, CVSS 7.1. EPSS: 0.4% chance of exploitation in the next 30 days.

libheif is an HEIF and AVIF file format decoder and encoder. Prior to version 1.21.0, a crafted HEIF that exercises the overlay image item path triggers a heap buffer over-read in `HeifPixelImage::overlay()`. The function computes a negative row length (likely from an unclipped overlay rectangle or invalid offsets), which then underflows when converted to `size_t` and is passed to `memcpy`, causing a very large read past the end of the source plane and a crash. Version 1.21.0 contains a patch. As a workaround, avoid decoding images using `iovl` overlay boxes.

Affected products

• Struktur Libheif: before 1.21.0 (fixed in 1.21.0)

Published 2025-12-29. Last modified 2026-10-07.