CVE-2026-67231Public exploitNetwork attack vectorHinoki check available

Authentication bypass via issuer-serial certificate matching

Published Sep 23, 2026 · Updated Sep 23, 2026

Authentication bypass in RabbitMQ Server before 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0 allows remote attackers to forge client identity. The trust-store verify_fun accepts a self-signed certificate when its attacker-controlled issuer DN and serial match an ETS whitelist entry, without comparing its key, fingerprint, signature, or DER. Exploitation requires the trust-store plugin as the TLS verifier and knowledge of a whitelisted issuer and serial; the forged certificate can complete TLS and authenticate as its chosen subject when certificate login is used.

CVSS severity9.1
Critical
EPSS probability0.25%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Authentication bypass in RabbitMQ Server before 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0 allows remote attackers to forge client identity. The trust-store verify_fun accepts a self-signed certificate when its attacker-controlled issuer DN and serial match an ETS whitelist entry, without comparing its key, fingerprint, signature, or DER. Exploitation requires the trust-store plugin as the TLS verifier and knowledge of a whitelisted issuer and serial; the forged certificate can complete TLS and authenticate as its chosen subject when certificate login is used.

The record

CVE
CVE-2026-67231
Published
Sep 23, 2026
Updated
Sep 23, 2026
Vendor
RabbitMQ
Product
RabbitMQ Server
Classifications
CWE-295, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=>= 3.13.0, < 3.13.15
  2. Affected versionversion=>= 4.0.0, < 4.0.20
  3. Affected versionversion=>= 4.1.0, < 4.1.11
  4. Affected versionversion=>= 4.2.0, < 4.2.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

RabbitMQ · RabbitMQ Serverversion=>= 3.13.0, < 3.13.15; version=>= 4.0.0, < 4.0.20; version=>= 4.1.0, < 4.1.11; version=>= 4.2.0, < 4.2.6

Published CVSS scores

9.1RabbitMQCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

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-295Improper Certificate Validation
T1078Valid Accounts

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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