CVE-2026-67411

RabbitMQ: Web MQTT with PROXY Protocol enabled: a loopback-only user permission bypass

Published: Sep 25, 2026Updated: Sep 25, 2026 Sources: CVE List NVDCWE-863

N/ACVSS

NVD MITRE

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.

No summary for this CVE yet.

Weaknesses

CWE-863

Affected Products

rabbitmq

oss-project·GBaka rabbitmq-server

rabbitmq-serverOn-prem

Databases / cache-message-queue

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques

Initial Access

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References

https://github.com/rabbitmq/rabbitmq-server/commit/a7528314840c4f8dc9904684f9f97ffa7aac6349

github.com

https://github.com/rabbitmq/rabbitmq-server/commit/edbead0eabbd65925d0dc914a22d6a29e155e646

github.com

https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9

github.com

and 2 more references View all →

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