CVE-2025-68431

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.

CVSS 3.1

7.1CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 36% of CVEs (scores of 2026-10-25)

CWEs

CWE-125, CWE-190

Published

2025-12-29

Modified

2026-10-07

Record from

the NVD, synced 2026-10-19

Affected

• struktur:libheif

References

• https://github.com/strukturag/libheif/commit/b8c12a7b70f46c9516711a988483bed377b78d46
• https://github.com/strukturag/libheif/releases/tag/v1.21.0
• https://github.com/strukturag/libheif/security/advisories/GHSA-j87x-4gmq-cqfq

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