CVE-2026-71418Network attack vectorHinoki check available

Monitoring interruption via retained DoH2 frame buffer

Published Sep 18, 2026 · Updated Sep 18, 2026

Algorithmic-complexity denial of service in Suricata 8.0.0 through 8.0.5 allows remote attackers to interrupt monitoring via crafted DoH2 traffic. The DNS-over-HTTP/2 handler in rust/src/http2/http2.rs reprocesses all retained DATA-frame contents because it fails to clear the directional buffer after each completed message. Any unauthenticated source able to send inspected DoH2 traffic can drive quadratic CPU use up to the 65 KiB buffer limit, degrading packet processing and monitoring visibility.

CVSS severity7.5
High
EPSS probability0.62%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Algorithmic-complexity denial of service in Suricata 8.0.0 through 8.0.5 allows remote attackers to interrupt monitoring via crafted DoH2 traffic. The DNS-over-HTTP/2 handler in rust/src/http2/http2.rs reprocesses all retained DATA-frame contents because it fails to clear the directional buffer after each completed message. Any unauthenticated source able to send inspected DoH2 traffic can drive quadratic CPU use up to the 65 KiB buffer limit, degrading packet processing and monitoring visibility.

The record

CVE
CVE-2026-71418
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
Open Information Security Foundation
Product
Suricata
Classifications
CWE-407, 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=>= 8.0.0, < 8.0.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Open Information Security Foundation · Suricataversion=>= 8.0.0, < 8.0.6

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-407Inefficient Algorithmic Complexity
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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