Buffer overflow in Struktur Libheif

CVE-2026-47178

libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.19.0 through 1.21.2, a crafted HEIF file (uncompressed `unci` codec, tiled, component-interleaved, 4:2:0) triggers a heap out-of-bounds write in libheif's uncompressed tile decoder. The write overwrites the C++ vtable pointer of an adjacent `unc_decoder_component_interleave` object; the next virtual call dispatches to an attacker-chosen address. Version 1.22.0 patches the issue.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (9.7th 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

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-47178?
CVE-2026-47178 is a medium-severity vulnerability in Struktur Libheif, classified under Out-of-bounds Write. CVSS score: 6.1/10. Published 2026-07-21.
How severe is CVE-2026-47178?
Medium severity. CVSS v3 base score is 6.1 out of 10.