Is CVE-2026-47251 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-47251 being exploited in the wild.

How severe is CVE-2026-47251?

Informational severity, with a CVSS score of 6.8, published 21 July 2026.

Is there a fix for CVE-2026-47251?

A patch was published on 2026-07-21: Version 1.22.0 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-47251 attacked?

It is attacked with local access, in a software library.

Am I affected by CVE-2026-47251?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-47251: libheif integer overflow in vvdec_push_data2

CVE-2026-47251 · Severity: info · CVSS 6.8 · Published 2026-07-21

libheif is a software library used by many applications to process HEIF and AVIF image files. A flaw in how the library handles certain video tracks (VVC) allows a specially crafted image file to crash the application or potentially expose small amounts of memory. This vulnerability is particularly notable because it exists within a security check that was intended to fix a previous bug, but was itself implemented incorrectly.

Quick answers

Is CVE-2026-47251 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-47251 being exploited in the wild.
How severe is CVE-2026-47251?: Informational severity, with a CVSS score of 6.8, published 21 July 2026.
Which products and versions are affected?: strukturag libheif <= 1.21.2.
Is there a fix for CVE-2026-47251?: A patch was published on 2026-07-21: Version 1.22.0 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-47251 attacked?: It is attacked with local access, in a software library.
Am I affected by CVE-2026-47251?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An integer overflow exists in the `vvdec_push_data2` function within `libheif/plugins/decoder_vvdec.cc`. The vulnerability occurs because the security check `if (frame_size < 4 + size)` uses 32-bit unsigned integer arithmetic; when `size` is near UINT32_MAX, the addition wraps around, bypassing the bounds check. An attacker can provide a crafted HEIF file with a VVC track containing a large size prefix to trigger an out-of-bounds heap read during a subsequent `std::vector::insert` operation. This can result in a denial-of-service (crash) or limited information disclosure. The issue was introduced as an incomplete fix for CVE-2026-3949 and is resolved in version 1.22.0.

Affected products

strukturag libheif <= 1.21.2

Timeline

2026-02-23: other: Vulnerability introduced in commit b97c8b5
2026-05-19: advisory: GitHub Security Advisory published
2026-07-21: disclosed: CVE-2026-47251 published to NVD
2026-07-21: patched: Version 1.22.0 released

References

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