CVE-2026-84446Public exploitNetwork attack vectorHinoki check available

Denial of service via oversized logical sample count

Published Sep 18, 2026 · Updated Sep 18, 2026

Denial of service in Struktur AG libheif before 1.23.2 allows remote attackers to hang decoding processes with crafted HEIF files. Track::init_sample_timing_table() leaves a repeat-amplified 64-bit output count above the 32-bit decode counters, so their termination comparison cannot succeed; related timing walks and untracked allocations also evade configured limits. Processing an attacker-supplied HEIF sequence is sufficient to sustain CPU use or exhaust memory, without authentication or user interaction.

CVSS severity7.5
High
EPSS probability0.46%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Denial of service in Struktur AG libheif before 1.23.2 allows remote attackers to hang decoding processes with crafted HEIF files. Track::init_sample_timing_table() leaves a repeat-amplified 64-bit output count above the 32-bit decode counters, so their termination comparison cannot succeed; related timing walks and untracked allocations also evade configured limits. Processing an attacker-supplied HEIF sequence is sufficient to sustain CPU use or exhaust memory, without authentication or user interaction.

The record

CVE
CVE-2026-84446
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
Struktur AG
Product
libheif
Classifications
CWE-835, T1499
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=< 1.23.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Struktur AG · libheifversion=< 1.23.2

Published CVSS scores

7.5GitHubCVSS: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-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499Endpoint Denial of Service

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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