---
id: CVE-2026-66080
title: RabbitMQ is a messaging and streaming broker
summary: >-
  RabbitMQ is a messaging and streaming broker. Prior to versions 4.1.11, 4.2.6,
  and 4.3.0, validate_partitions only checks that the requested partition count
  is at least 1, with no upper bound. A large count such as lists:seq(0,
  500000000…
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-770
vendor: rabbitmq
product: rabbitmq-server
affected:
  - 'rabbitmq-server >= 4.1.0, < 4.1.11'
  - 'rabbitmq-server >= 4.2.0, < 4.2.6'
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T21:16:59.787'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-66080'
references:
  - url: 'https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6'
    label: security-advisories@github.com
  - url: 'https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-wg79-5449-m728
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-09-23T20:32:10.758Z'
---

## Overview

RabbitMQ is a messaging and streaming broker. Prior to versions 4.1.11, 4.2.6, and 4.3.0, validate_partitions only checks that the requested partition count is at least 1, with no upper bound. A large count such as lists:seq(0, 500000000) allocates roughly 8GB. Preconditions include The rabbitmq_stream_management plugin must be enabled. The caller needs the management tag and access to the target vhost.. This issue is fixed in versions 4.1.11, 4.2.6, and 4.3.0.

## Remediation

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