Incorrect authorization in RabbitMQ Server - #VU139292
Published: July 24, 2026
Vulnerability identifier: #VU139292
CSH Severity: Low
CVSS v4 BT: 2.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: N/A
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to bypass loopback-only user restrictions and authenticate to the MQTT service.
The vulnerability exists due to incorrect authorization in rabbit_web_mqtt_handler and rabbit_mqtt_processor when processing MQTT and MQTT over WebSocket connections behind a trusted PROXY Protocol frontend. A remote user can connect through the trusted frontend using valid credentials for a loopback-restricted account to bypass loopback-only user restrictions and authenticate to the MQTT service.
Exploitation requires `web_mqtt.proxy_protocol = true`, a reachable trusted frontend, and valid credentials for a loopback-restricted account.
Affected software
RabbitMQ Server
Remediation
Install security update from vendor's website.
RabbitMQ Server - addressed in versions 3.13.18, 4.0.23, 4.1.14, 4.2.9, 4.3.3