# CVE-2026-50142

## Summary

- **CVE ID:** CVE-2026-50142
- **Severity:** HIGH
- **CVSS Score:** 7.5 (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:** Aug 18, 2026
- **Last Modified:** Sep 14, 2026

## Description

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.

## Affected Products

- strukturag — libheif (>= 1.19.0, < 1.23.0)

## References

- [CNA](https://github.com/strukturag/libheif/security/advisories/GHSA-jvmp-j3cw-84mh)
- [CNA](https://github.com/strukturag/libheif/commit/a6caa38f7a70d66dc9caec2a7bfe20935b32c622)
- [CNA](https://github.com/strukturag/libheif/releases/tag/v1.23.0)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.56%
- **EPSS Percentile:** 44.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._