---
id: CVE-2026-84447
title: libheif is a HEIF and AVIF file format decoder and encoder
summary: >-
  libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.1 and
  earlier, crafted grid, iovl, and iden reference graphs can repeatedly decode
  the same base image because processed_ids is copied per branch and
  ImageItem::decode_i…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-770
vendor: strukturag
product: libheif
affected:
  - libheif < 1.23.2
published: '2026-09-18'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:17:17.017'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84447'
references:
  - url: >-
      https://github.com/strukturag/libheif/commit/30b52a4e829efe0ee6d7208e8500b99f664af5e9
    label: security-advisories@github.com
  - url: 'https://github.com/strukturag/libheif/releases/tag/v1.23.2'
    label: security-advisories@github.com
  - url: >-
      https://github.com/strukturag/libheif/security/advisories/GHSA-x8xm-cm2c-cfc8
    label: security-advisories@github.com
  - url: >-
      https://github.com/strukturag/libheif/security/advisories/GHSA-x8xm-cm2c-cfc8
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-18T17:29:29.218555Z'
ingestedAt: '2026-09-18T16:45:41.394Z'
epss: 0.00609
epssPercentile: 0.46842
---

## Overview

libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.1 and earlier, crafted grid, iovl, and iden reference graphs can repeatedly decode the same base image because processed_ids is copied per branch and ImageItem::decode_image() has no shared operation budget. This vulnerability is fixed in 1.23.2.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.