CVE-2026-47178: libheif Memory Corruption

Description

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.

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CVSS v3.1 Score

6.1

MEDIUM

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

EPSS — Exploit Prediction

0.0020

Probability of exploitation

0.10%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

Affected Products

Vendor	Product	Versions
struktur	libheif	1.19.0 — 1.22.0

References

Advisories & Patches

https://github.com/strukturag/libheif/security/advisories/GHSA-5x55-x5pf-9c6g

Exploits

https://github.com/strukturag/libheif/security/advisories/GHSA-5x55-x5pf-9c6g

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 6.1 (MEDIUM).

How severe is CVE-2026-47178? +

CVE-2026-47178 has a CVSS v3.1 score of 6.1 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0020, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-47178? +

CVE-2026-47178 affects products from struktur, specifically: libheif. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-47178? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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