---
id: CVE-2026-67411
title: RabbitMQ is a messaging and streaming broker
summary: >-
  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 th…
severity: medium
cvss: 6
cvssVector: 'CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-863
vendor: rabbitmq
product: rabbitmq-server
affected:
  - 'rabbitmq-server >= 4.3.0, < 4.3.3'
  - 'rabbitmq-server >= 4.2.0, < 4.2.9'
  - 'rabbitmq-server >= 4.1.0, < 4.1.14'
  - 'rabbitmq-server >= 4.0.0, < 4.0.23'
  - 'rabbitmq-server >= 3.13.0, < 3.13.18'
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T17:17:13.237'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-67411'
references:
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/commit/a7528314840c4f8dc9904684f9f97ffa7aac6349
    label: security-advisories@github.com
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/commit/edbead0eabbd65925d0dc914a22d6a29e155e646
    label: security-advisories@github.com
  - url: 'https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9'
    label: security-advisories@github.com
  - url: 'https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3'
    label: security-advisories@github.com
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-4r6f-9cpw-f6g6
    label: security-advisories@github.com
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-4r6f-9cpw-f6g6
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-25T16:55:11.064286Z'
cvssSource: cna
ingestedAt: '2026-09-25T17:13:14.011Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.