PT-2026-36267 · Julia · Libheif Jll

Published 2026-04-20 · Updated 2026-04-20

OSV

CVSS v3.1

6.5

Medium

Base vector

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

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.

Fix

Related Identifiers

JLSEC-2026-156

Affected Products

Libheif Jll

References · 4

• https://osv.dev/vulnerability/JLSEC-2026-156 · Vendor Advisory
• https://github.com/strukturag/libheif/security/advisories/GHSA-j87x-4gmq-cqfq · Note
• https://github.com/strukturag/libheif/releases/tag/v1.21.0 · Note
• https://github.com/strukturag/libheif/commit/b8c12a7b70f46c9516711a988483bed377b78d46 · Note