CVE-2026-94083Network attack vector

Engine crash via DoH2 protocol-state confusion

Published Sep 20, 2026 · Updated Sep 20, 2026

Type confusion in Suricata 8.0.0 through 8.0.6 allows remote attackers to crash the engine via a crafted DoH2 protocol upgrade. During a same-packet HTTP1-to-HTTP2-to-DoH2 transition, SCAppLayerForceProtocolChange overwrites alproto_orig before the HTTP1 state is freed, so cleanup treats HTTP1 state as HTTP2 and performs an invalid free. The flaw requires app-layer.protocols.doh2, which is enabled by default in Suricata 8.x; crafted monitored traffic needs no Suricata login.

CVSS severity9.4
Critical
EPSS probability0.54%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Type confusion in Suricata 8.0.0 through 8.0.6 allows remote attackers to crash the engine via a crafted DoH2 protocol upgrade. During a same-packet HTTP1-to-HTTP2-to-DoH2 transition, SCAppLayerForceProtocolChange overwrites alproto_orig before the HTTP1 state is freed, so cleanup treats HTTP1 state as HTTP2 and performs an invalid free. The flaw requires app-layer.protocols.doh2, which is enabled by default in Suricata 8.x; crafted monitored traffic needs no Suricata login.

The record

CVE
CVE-2026-94083
Published
Sep 20, 2026
Updated
Sep 20, 2026
Vendor
Open Information Security Foundation
Product
Suricata
Classifications
CWE-843, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 20, 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 <8.0.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Open Information Security Foundation · Suricataversion=8.0.0 <8.0.7

Published CVSS scores

9.4MITRECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L

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-843Access of Resource Using Incompatible Type ('Type Confusion')
T1499.004Endpoint Denial of Service: Application 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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