CVE-2026-50142 PUBLISHED

libheif: unbounded heap allocation in HEIF sequence parser (stsz fixed-size mode missing bound check)

Assigner: GitHub_M
Reserved: 03.06.2026 Published: 18.08.2026 Updated: 18.08.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 7.5

Product Status

Vendor strukturag
Product libheif
Versions
  • Version >= 1.19.0, < 1.23.0 is affected

References

Problem Types

  • CWE-190: Integer Overflow or Wraparound CWE
  • CWE-770: Allocation of Resources Without Limits or Throttling CWE