---
id: CVE-2026-67227
title: RabbitMQ is a messaging and streaming broker
summary: >-
  RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.0.22 and
  4.1.14 and 4.2.7 and 4.3.1, Atom exhaustion: toatom on global-parameter :name.
  resourceexists/2 (and the PUT/DELETE handlers) call
  rabbitdatacoercion:toatom/1 on t…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'
cwe:
  - CWE-400
vendor: rabbitmq
product: rabbitmq-server
affected:
  - 'rabbitmq-server >= 4.0.0, < 4.0.22'
  - 'rabbitmq-server >= 4.1.0, < 4.1.14'
  - 'rabbitmq-server >= 4.2.0, < 4.2.7'
  - 'rabbitmq-server >= 4.3.0, < 4.3.1'
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T18:17:29.713'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-67227'
references:
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/commit/8fbe6d8112427e85fb9a9206b3eb6e9a3ddd3e39
    label: security-advisories@github.com
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/commit/fc591e7ee27a29657ca960930acefd3e4217e007
    label: security-advisories@github.com
  - url: 'https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.7'
    label: security-advisories@github.com
  - url: 'https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q7x8-97rh-cr24
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-25T17:47:50.875187Z'
cvssSource: cna
ingestedAt: '2026-09-25T17:13:14.021Z'
---

## Overview

RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.0.22 and 4.1.14 and 4.2.7 and 4.3.1, Atom exhaustion: toatom on global-parameter :name. resourceexists/2 (and the PUT/DELETE handlers) call rabbitdatacoercion:toatom/1 on the :name URL path segment. toatom/1 uses binarytoatom/2 (unsafe). The endpoint requires policymaker (not management, but below A user with the policymaker tag can crash the node by exhausting the atom table via repeated requests to /api/global-parameters/:name with unique :name Management plugin enabled policymaker tag ~1M HTTP. This issue is fixed in versions 4.0.22 and 4.1.14 and 4.2.7 and 4.3.1.

## Remediation

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