---
id: CVE-2026-67419
title: RabbitMQ is a messaging and streaming broker
summary: >-
  RabbitMQ is a messaging and streaming broker. Prior to 4.3.5, an authenticated
  user who can bind a queue to a topic exchange and publish to it can use
  consecutive # segments in a binding key to make both topic matchers revisit
  the same t…
severity: high
cvss: 7.1
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'
cwe:
  - CWE-407
  - CWE-1333
vendor: rabbitmq
product: rabbitmq-server
affected:
  - rabbitmq-server < 4.3.5
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T18:17:30.443'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-67419'
references:
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/commit/c5ed7c4e97e02be688730803604cc7a88dbe4864
    label: security-advisories@github.com
  - url: 'https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.5'
    label: security-advisories@github.com
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-h964-v5mf-22cq
    label: security-advisories@github.com
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-h964-v5mf-22cq
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-25T17:01:28.563642Z'
cvssSource: cna
ingestedAt: '2026-09-25T17:13:14.018Z'
---

## Overview

RabbitMQ is a messaging and streaming broker. Prior to 4.3.5, an authenticated user who can bind a queue to a topic exchange and publish to it can use consecutive # segments in a binding key to make both topic matchers revisit the same trie-node and routing-key-suffix states without memoization. The matcher materializes duplicate destinations before deduplication, causing combinatorial CPU work and memory pressure that can disrupt routing for all tenants. This vulnerability is fixed in 4.3.5.

## Remediation

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