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

Vulnerability summary

CVE-2025-68431 is a high (CVSS 7.1) Out-of-bounds Read vulnerability in struktur libheif. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.5% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 29-12-2025
   PublishedVulnerability first disclosed.
2. 30-12-2025
   Last modifiedVulnerability information updated.

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.

• CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.
• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.