CVE-2026-32740

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

HIGH
8.8
CVSS Score
Published: May 19, 2026 at 07:22 PM UTC
Updated: July 24, 2026 at 09:23 AM UTC
2 products affected across 2 vendorsLibheifLibheif

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Severity
HIGH8.8
Exploit prediction
EPSS 0.7%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.22.0
Affected range stops below 1.22.0, so it looks safe — our inference, not a vendor statement
v < 1.22.0
Affected range stops below 1.22.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (5)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/strukturag/libheif/security/advisories/GHSA-frfr-f3vg-2g6j
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/strukturag/libheif/releases/tag/v1.22.0
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/security/cve/CVE-2026-32740
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://bugzilla.redhat.com/show_bug.cgi?id=2479969

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-787

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