# CVE-2026-62377

## Summary

- **CVE ID:** CVE-2026-62377
- **Severity:** MEDIUM
- **CVSS Score:** 4.3 (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:** Aug 18, 2026
- **Last Modified:** Aug 19, 2026

## Description

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.

## Affected Products

- strukturag — libheif (< 1.23.1)

## References

- [CNA](https://github.com/strukturag/libheif/security/advisories/GHSA-9ww4-9v47-m7pj)
- [CNA](https://github.com/strukturag/libheif/issues/1844)
- [CNA](https://github.com/strukturag/libheif/commit/e1a0bc1c1ae74f8075eaca30a1cdb2b9bee698d3)
- [CNA](https://github.com/strukturag/libheif/releases/tag/v1.23.1)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.33%
- **EPSS Percentile:** 25.4

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._