CVE-2026-67409: rabbitmq-server Vulnerability (CVSS 8.2)

Description

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 4.3.3, 4.2.9, 4.1.14, 4.0.23, and 3.13.18, JWKS Fetch Ignores HTTP Response Status Code - Signing Key Destruction Causes Authentication DoS (CWE-252). the JWKS key fetching mechanism in uaajwt.erl does not validate the HTTP response status code when downloading signing keys from the OAuth2 provider's JWKS endpoint. Non-200 responses (including 4xx and 5xx errors) are processed identically to successful responses. When the JWKS endpoint returns an error response with a valid-JSON body that lacks a keys field, all previously cached signing keys are destroyed, causing a persistent authentication denial of Files: deps/rabbitmqauthbackendoauth2/src/uaajwt.erl, lines 50-63 deps/rabbitmqauthbackendoauth2/src/uaajwks.erl, lines 5-7 deps/rabbitmqauthbackendoauth2/src/rabbitoauth2provider.erl, lines 98-107 Bug 1: HTTP status code ignored (uaajwt.erl:50-63): The Erlang httpc module returns {ok, {{HttpVersion, StatusCode, ReasonPhrase}, Headers, Body}}. The pattern {ok, {, , JwksBody}} matches ANY successful HTTP transaction Persistent authentication DoS: Once keys are destroyed, ALL OAuth2/JWT authentication fails for all users until a new successful JWKS refresh occurs Amplification: A single attacker can deny access to all legitimate OAuth2 users across the entire RabbitMQ. This issue is fixed in versions 4.3.3, 4.2.9, 4.1.14, 4.0.23, and 3.13.18.

Metrics

CVSS 4.0

8.2/10

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Weakness Enumeration

CWE-252

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
rabbitmq	rabbitmq-server	>= 4.3.0, < 4.3.3; >= 4.2.0, < 4.2.9; >= 4.1.0, < 4.1.14; >= 4.0.0, < 4.0.23; >= 3.13.0, < 3.13.18

References

Timeline

Published: Sep 25, 2026
Last Modified: Sep 25, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-67409?

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 4.3.3, 4.2.9, 4.1.14, 4.0.23, and 3.13.18, JWKS Fetch Ignores HTTP Response Status Code - Signing Key Destruction Causes Authentication DoS (CWE-252). the JWKS key fetching mechanism in uaajwt.erl does not validate the HTTP response status code when downloading signing keys from the OAuth2 provider's JWKS endpoint. Non-200 responses (including 4xx and 5xx errors) are processed identically to successful responses. When the JWKS endpoint returns an error response with a valid-JSON body that lacks a keys field, all previously cached signing keys are destroyed, causing a persistent authentication denial of Files: deps/rabbitmqauthbackendoauth2/src/uaajwt.erl, lines 50-63 deps/rabbitmqauthbackendoauth2/src/uaajwks.erl, lines 5-7 deps/rabbitmqauthbackendoauth2/src/rabbitoauth2provider.erl, lines 98-107 Bug 1: HTTP status code ignored (uaajwt.erl:50-63): The Erlang httpc module returns {ok, {{HttpVersion, StatusCode, ReasonPhrase}, Headers, Body}}. The pattern {ok, {, , JwksBody}} matches ANY successful HTTP transaction Persistent authentication DoS: Once keys are destroyed, ALL OAuth2/JWT authentication fails for all users until a new successful JWKS refresh occurs Amplification: A single attacker can deny access to all legitimate OAuth2 users across the entire RabbitMQ. This issue is fixed in versions 4.3.3, 4.2.9, 4.1.14, 4.0.23, and 3.13.18.

How severe is CVE-2026-67409?

CVE-2026-67409 has a CVSS score of 8.2/10 (HIGH severity).

How do I fix CVE-2026-67409?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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