CVE-2026-67409Public exploitNetwork attack vectorHinoki check available

Authentication denial via unchecked JWKS response status

Published Sep 25, 2026 · Updated Sep 25, 2026

Denial of service in RabbitMQ Server allows remote attackers to interrupt OAuth2 authentication with a JWT containing an unknown key ID. The uaa_jwt.erl fetch path accepts non-200 JWKS responses as successful, decodes a missing keys field as an empty set, and replaces cached dynamic signing keys. Exploitation requires JWKS-based OAuth2 authentication and a degraded endpoint returning valid JSON; one unauthenticated AMQP request can then block every OAuth2 user until a successful refresh.

CVSS severity8.2
High
EPSS probability0.42%
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 RabbitMQ Server allows remote attackers to interrupt OAuth2 authentication with a JWT containing an unknown key ID. The uaa_jwt.erl fetch path accepts non-200 JWKS responses as successful, decodes a missing keys field as an empty set, and replaces cached dynamic signing keys. Exploitation requires JWKS-based OAuth2 authentication and a degraded endpoint returning valid JSON; one unauthenticated AMQP request can then block every OAuth2 user until a successful refresh.

The record

CVE
CVE-2026-67409
Published
Sep 25, 2026
Updated
Sep 25, 2026
Vendor
RabbitMQ
Product
RabbitMQ Server
Classifications
CWE-252, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 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=>= 3.13.0, < 3.13.18
  2. Affected versionversion=>= 4.0.0, < 4.0.23
  3. Affected versionversion=>= 4.1.0, < 4.1.14
  4. Affected versionversion=>= 4.2.0, < 4.2.9
  5. Affected versionversion=>= 4.3.0, < 4.3.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

RabbitMQ · RabbitMQ Serverversion=>= 3.13.0, < 3.13.18; version=>= 4.0.0, < 4.0.23; version=>= 4.1.0, < 4.1.14; version=>= 4.2.0, < 4.2.9; version=>= 4.3.0, < 4.3.3

Published CVSS scores

8.2RabbitMQCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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-252Unchecked Return Value
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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