---
id: CVE-2026-50142
title: libheif is a HEIF and AVIF file format decoder and encoder
summary: >-
  libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until
  1.23.0, a crafted HEIF sequence accepted by heif_context_read_from_memory()
  with the msf1 sequence brand can cause unbounded heap allocation. In
  libheif/sequen…
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-190
  - CWE-770
published: '2026-08-18'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:13:25.910'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-50142'
references:
  - url: >-
      https://github.com/strukturag/libheif/commit/a6caa38f7a70d66dc9caec2a7bfe20935b32c622
    label: security-advisories@github.com
  - url: 'https://github.com/strukturag/libheif/releases/tag/v1.23.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/strukturag/libheif/security/advisories/GHSA-jvmp-j3cw-84mh
    label: security-advisories@github.com
tags:
  - nvd
  - exploit-available
epss: 0.00655
epssPercentile: 0.49246
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/MuhammedHussein17/libheif-cve-2026-50142'
  checkedAt: '2026-09-26T09:05:47.025Z'
exploitAvailable: true
ingestedAt: '2026-09-09T21:22:45.538Z'
---

## Overview

libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.0, a crafted HEIF sequence accepted by heif_context_read_from_memory() with the msf1 sequence brand can cause unbounded heap allocation. In libheif/sequences/seq_boxes.cc, Box_stsz::parse() applies max_sequence_frames only to variable-size samples, so fixed-size mode accepts an attacker-controlled sample_count without a bound. In libheif/sequences/track.cc, Track::load() also adds current_sample_idx and samples_per_chunk in 32-bit arithmetic, allowing the consistency check to be bypassed by wraparound. The resulting values reach the Chunk::Chunk() allocation path, which can consume gigabytes of memory and crash or stall the process through memory exhaustion. This issue is fixed in version 1.23.0.

## Remediation

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