High · published September 25, 2026
RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3, native MQTT and MQTT over WebSocket behind a trusted PROXY Protocol frontend could lose the proxy-derived client address before the MQTT authentication path checked loopback_users, causing the frontend-to-broker address to be treated as loopback. An attacker who can reach the trusted frontend and has valid credentials for a loopback-restricted account can therefore bypass the source-address restriction; the issue does not bypass password authentication. This issue is fixed in versions 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3.
| Product | Versions | Fixed in |
|---|---|---|
| broadcom/rabbitmq_server | ≥ 3.13.0, < 3.13.18 | 3.13.18 |
| broadcom/rabbitmq_server | ≥ 4.0.0, < 4.0.23 | 4.0.23 |
| broadcom/rabbitmq_server | ≥ 4.1.0, < 4.1.14 | 4.1.14 |
| broadcom/rabbitmq_server | ≥ 4.2.0, < 4.2.9 | 4.2.9 |
| broadcom/rabbitmq_server | ≥ 4.3.0, < 4.3.3 | 4.3.3 |