RabbitMQ: OAuth2 Client Secret Exposed via Unauthenticated JavaScript Endpoint

Summary

RabbitMQ is a messaging and streaming broker. From 4.2.0 until 4.3.3 and 4.2.9, OAuth2 Client Secret Exposed via Unauthenticated JavaScript Endpoint (CWE-200). when OAuth2 authentication is enabled for the RabbitMQ Management UI and the configured flow, IDP use a client secret, the oauthclientsecret configuration value is included in the JavaScript served by the unauthenticated endpoint /js/oidc-oauth/bootstrap.js. Any user who can reach the management UI port can retrieve the OAuth2 client secret without Files: deps/rabbitmqmanagement/src/rabbitmgmtwmauth.erl, line 186 deps/rabbitmqmanagement/src/rabbitmgmtoauthbootstrap.erl, lines 35-50 deps/rabbitmqmanagement/src/rabbitmgmtdispatcher.erl, lines 45-49 (route registration) Code Path: 1. The route /js/oidc-oauth/bootstrap.js is registered as a plain Cowboy handler (rabbitmgmtdispatcher.erl:46): Credential exposure for the affected configuration: OAuth2 client secret is accessible without any authentication Token theft: Attacker can complete the authorization code flow using stolen authorization codes Client impersonation: Attacker can make requests. Any RabbitMQ deployment with: This issue is fixed in versions 4.3.3 and 4.2.9.

Timeline

1. Sep 25, 2026, 4:32 PM UTCCVE published
2. Sep 25, 2026, 5:45 PM UTCCISA SSVC assessment

   Exploitation: poc · Automatable: no · Technical impact: partial

3. Sep 25, 2026, 5:46 PM UTCRecord last updated

Affected versions

• rabbitmq rabbitmq-server

  From 4.3.0 · fixed in 4.3.3; From 4.2.0 · fixed in 4.2.9

• rabbitmqBitnami

  From 4.2.0 · fixed in 4.2.9; From 4.3.0 · fixed in 4.3.3

References 5