CVE-2025-68431: libheif Out-of-bounds Read

Description

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.

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CVSS v3.1 Score

6.5

MEDIUM

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

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

CWE-190 Integer Overflow

Affected Products

Vendor	Product	Versions
struktur	libheif	< 1.21.0

References

Advisories & Patches

https://github.com/strukturag/libheif/commit/b8c12a7b70f46c9516711a988483bed377b78d46 https://github.com/strukturag/libheif/security/advisories/GHSA-j87x-4gmq-cqfq

Exploits

https://github.com/strukturag/libheif/security/advisories/GHSA-j87x-4gmq-cqfq

Other References

https://github.com/strukturag/libheif/releases/tag/v1.21.0

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2025-68431? +

CVE-2025-68431 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-68431? +

CVE-2025-68431 affects products from struktur, specifically: libheif. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-68431? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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