Out-of-bounds Read in Struktur Libheif
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (35.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 35.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Struktur Libheif
- Strukturag Libheif — versions < 1.21.0
Weakness classification (CWE)
References
- github.com/strukturag/libheif/security/advisories/GHSA-j87x-4gmq-cqfq (Exploit, Patch, Vendor Advisory)
- github.com/strukturag/libheif/commit/b8c12a7b70f46c9516711a988483bed377b78d46 (Patch)
- github.com/strukturag/libheif/releases/tag/v1.21.0 (Product, Release Notes)
Frequently asked questions
- What is CVE-2025-68431?
- CVE-2025-68431 is a medium-severity vulnerability in Struktur Libheif, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2025-12-29.
- How severe is CVE-2025-68431?
- Medium severity. CVSS v3 base score is 6.5 out of 10.