CVE-2026-67409

Medium

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.

SeverityMedium
CVSS6.5
Exploit probability—
ProductBroadcom Rabbitmq Server
PublishedSep 25, 2026
First seenSep 25, 2026
Weakness typeCWE-252CWE-252

How to fix

Update
  • broadcom rabbitmq_server3.13.18, 4.0.23, 4.1.14, 4.2.9, 4.3.3 or later

Affected products

ProductAffected versionsFixed in
broadcom rabbitmq_server3.13.0 ≤ v < 3.13.18, 4.0.0 ≤ v < 4.0.23, 4.1.0 ≤ v < 4.1.14, 4.2.0 ≤ v < 4.2.9, 4.3.0 ≤ v < 4.3.33.13.18, 4.0.23, 4.1.14, 4.2.9, 4.3.3

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CVE-2026-67409 · Broadcom Rabbitmq Server · Dark Radar