Is CVE-2026-84384 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-84384 being exploited in the wild.

How severe is CVE-2026-84384?

High severity, with a CVSS score of 7.5, published 18 September 2026.

Which products and versions are affected?

struktur AG Libheif 1.19.0 to 1.23.1.

Is there a fix for CVE-2026-84384?

A patch was published on 2026-08-24: Fix committed to master branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-84384 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-84384?

Check whether you run struktur AG Libheif at an affected version. 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-2026-84384: libheif decompression bomb via brotli/zlib metadata

CVE-2026-84384 · Severity: high · CVSS 7.5 · Published 2026-09-18

libheif is a decoder and encoder for HEIF and AVIF image formats. A crafted image file with compressed metadata can cause the library to decompress data without size limits, consuming unbounded memory and crashing the application. An attacker can create a small malicious image file that triggers this denial-of-service when opened.

Technologies: struktur AG Libheif. Vendors: struktur AG.

Quick answers

Is CVE-2026-84384 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-84384 being exploited in the wild.
How severe is CVE-2026-84384?: High severity, with a CVSS score of 7.5, published 18 September 2026.
Which products and versions are affected?: struktur AG Libheif 1.19.0 to 1.23.1.
Is there a fix for CVE-2026-84384?: A patch was published on 2026-08-24: Fix committed to master branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-84384 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-84384?: Check whether you run struktur AG Libheif at an affected version. 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

The vulnerability exists in decompress_brotli() and do_inflate() functions which lack effective output-size bounds. The brotli path has no output limit, while the zlib path only checks a small temporary buffer in a code branch that valid streams do not reach. Additionally, overlapping ICEF units can decompress the same payload repeatedly, amplifying memory consumption. HeifContext::interpret_heif_file_images() processes multiple compressed metadata items during file opening, allowing an attacker-crafted file to exhaust memory during the parse phase.

Affected products

Struktur AG libheif 1.19.0 to 1.23.1

Timeline

2026-09-18: disclosed: CVE-2026-84384 published
2026-08-24: patched: Fix committed to master branch
2026-08-25: patched: Version 1.23.2 released with security fix

References

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