Description
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:NWeakness enumeration
Affected software
| 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
- https://github.com/rabbitmq/rabbitmq-server/commit/a7528314840c4f8dc9904684f9f97ffa7aac6349Patch
- https://github.com/rabbitmq/rabbitmq-server/commit/edbead0eabbd65925d0dc914a22d6a29e155e646Patch
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9Release Notes
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3Release Notes
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-4r6f-9cpw-f6g6Exploit, Vendor Advisory
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-4r6f-9cpw-f6g6Exploit, Vendor Advisory
Timeline
- Published
- Sep 25, 2026
- Last modified
- Oct 8, 2026
- NVD status
- Analyzed