---
id: CVE-2026-62377
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 1.23.0 and
  earlier, a crafted HEIF sequence accepted by heif_context_read_from_memory()
  can leave the context with no registered sequence tracks and crash when
  heif_context_g…
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L'
cwe:
  - CWE-617
  - CWE-908
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-2026-62377'
references:
  - url: >-
      https://github.com/strukturag/libheif/commit/e1a0bc1c1ae74f8075eaca30a1cdb2b9bee698d3
    label: security-advisories@github.com
  - url: 'https://github.com/strukturag/libheif/issues/1844'
    label: security-advisories@github.com
  - url: 'https://github.com/strukturag/libheif/releases/tag/v1.23.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/strukturag/libheif/security/advisories/GHSA-9ww4-9v47-m7pj
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00413
epssPercentile: 0.32853
ingestedAt: '2026-09-09T21:22:45.538Z'
---

## Overview

libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.0 and earlier, a crafted HEIF sequence accepted by heif_context_read_from_memory() can leave the context with no registered sequence tracks and crash when heif_context_get_track(ctx, 0) is called. HeifContext::get_track() in libheif/context.cc executes assert(has_sequence()) before its normal error handling, so assert-enabled builds abort instead of allowing the public wrapper in libheif/api/libheif/heif_sequences.cc to return null. In release builds, removing the assertion lets the track_id zero path dereference m_tracks.begin()->second on an empty map, which is undefined behavior and typically crashes. The issue is reachable through documented public APIs after parsing attacker-controlled bytes. This issue is fixed in version 1.23.1.

## Remediation

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