CVE-2026-84384Public exploitNetwork attack vectorHinoki check available

Parser crash via unbounded metadata decompression

Published Sep 18, 2026 · Updated Sep 18, 2026

Resource exhaustion in Struktur AG libheif 1.19.0 through 1.23.1 allows remote attackers to crash parsers with crafted HEIF or AVIF files. decompress_brotli() appends to an output vector without a bound, while do_inflate() checks a reset 8 KB buffer instead of accumulated output. Opening one file is sufficient when brotli metadata compression is available; the resulting unbounded allocation can abort the host process.

CVSS severity7.5
High
EPSS probability0.52%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Resource exhaustion in Struktur AG libheif 1.19.0 through 1.23.1 allows remote attackers to crash parsers with crafted HEIF or AVIF files. decompress_brotli() appends to an output vector without a bound, while do_inflate() checks a reset 8 KB buffer instead of accumulated output. Opening one file is sufficient when brotli metadata compression is available; the resulting unbounded allocation can abort the host process.

The record

CVE
CVE-2026-84384
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
Struktur AG
Product
libheif
Classifications
CWE-409, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 1.19.0, < 1.23.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Struktur AG · libheifversion=>= 1.19.0, < 1.23.2

Published CVSS scores

7.5GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-409Improper Handling of Highly Compressed Data (Data Amplification)
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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