Out-of-bounds Read in Struktur Libheif
CVE-2026-47254
libheif is a HEIF and AVIF file format decoder and encoder. Prior to version 1.22.0, `Track::init_sample_timing_table()` in `libheif/sequences/track.cc` stores an out-of-bounds chunk index (`m_chunks.size()`) into `m_presentation_timeline` when the number of chunks defined in the `stco` box is less than the number of samples in `stsz`. A subsequent call to `heif_track_get_next_raw_sequence_sample()` reads `m_chunks[chunk_idx]` with that OOB index, causing a heap-buffer-overflow. Version 1.22.0 fixes the issue.
Vulnerability class: Buffer Overflow
EPSS: 0.002 (8.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H.
Affected products
- Struktur Libheif
- Strukturag Libheif — versions < 1.22.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-47254?
- CVE-2026-47254 is a medium-severity vulnerability in Struktur Libheif, classified under Out-of-bounds Read. CVSS score: 6.1/10. Published 2026-07-21.
- How severe is CVE-2026-47254?
- Medium severity. CVSS v3 base score is 6.1 out of 10.