CVE-2026-67410: RabbitMQ: OAuth2 Client Secret Exposed via Unauthenticated JavaScript Endpoint

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-09-25 · updated 2026-10-08
Weakness: CWE-200

Description

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.

Affected products

rabbitmq-server: from 4.2.0 before 4.2.9; from 4.3.0 before 4.3.3 — fixed in 4.2.9, 4.3.3

How to fix

Upgrade to a fixed version: rabbitmq-server 4.2.9, 4.3.3. Check the vendor advisory for mitigations.

References

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