What’s Vulnerable › Vulnerabilities

CVE-2026-32740: libheif: Heap-Buffer-Overflow Write in Grid Tile Chroma Compositing

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-05-19 · updated 2026-07-24
• Weakness: CWE-787

Description

libheif is a HEIF and AVIF file format decoder and encoder. Versions 1.21.2 and prior contain a heap-buffer-overflow (write) vulnerability in the grid tile compositing, allowing an attacker to write 64 bytes of fully attacker-controlled data past the end of a chroma plane heap allocation by crafting a HEIF/AVIF file with a 1×4 grid of odd-height tiles. The overflow is triggered during normal image decoding with default build configuration. The written bytes are chroma (Cb/Cr) pixel values from the attacking tile, giving the attacker full control over the overflow content. This issue has been fixed in version 1.22.0.

Affected products

• strukturag libheif: before 1.22.0 — fixed in 1.22.0

How to fix

Upgrade to a fixed version: strukturag libheif 1.22.0. Check the vendor advisory for mitigations.

References

• https://github.com/strukturag/libheif/releases/tag/v1.22.0
• https://github.com/strukturag/libheif/security/advisories/GHSA-frfr-f3vg-2g6j
• https://access.redhat.com/security/cve/CVE-2026-32740
• https://bugzilla.redhat.com/show_bug.cgi?id=2479969
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32740.json

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