---
id: CVE-2026-67235
title: RabbitMQ is a messaging and streaming broker
summary: >-
  RabbitMQ is a messaging and streaming broker. Prior to versions 4.3.0, 4.2.6,
  4.1.11, 4.0.20, and 3.13.15, The content-header BodySize (a uint64) was stored
  without validation against max_message_size. The size check ran only when
  assemb…
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-770
vendor: rabbitmq
product: rabbitmq-server
affected:
  - 'rabbitmq-server >= 4.2.0, < 4.2.6'
  - 'rabbitmq-server >= 4.1.0, < 4.1.11'
  - 'rabbitmq-server >= 4.0.0, < 4.0.20'
  - 'rabbitmq-server >= 3.13.0, < 3.13.15'
patched:
  - hardened_images
published: '2026-09-23'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T16:17:09.667'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-67235'
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-q8g2-pc7m-m3jw
    label: security-advisories@github.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-67235.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-67235'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2539784'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-67235'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-67235'
  - url: 'https://access.redhat.com/errata/RHSA-2026:67552'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-24T13:58:54.889361Z'
cvssSource: cna
scores:
  cna: 7.1
  vendor: 6.5
ingestedAt: '2026-09-23T21:33:13.531Z'
epss: 0.00259
epssPercentile: 0.15749
---

## Overview

RabbitMQ is a messaging and streaming broker. Prior to versions 4.3.0, 4.2.6, 4.1.11, 4.0.20, and 3.13.15, The content-header BodySize (a uint64) was stored without validation against max_message_size. The size check ran only when assembly completed. By declaring body_size = 2^63-1 and then streaming fragments, a client ensured that check_msg_size never fired, so the accumulated body size went unbounded. A reader process accumulates memory until the memory alarm fires, degrading all publishers cluster-wide, or until the node runs out of memory. The memory alarm provides only partial mitigation, since it is reactive rather than preventive. AMQP 0-9-1 is the most widely used protocol, and any publisher can trigger this condition. Preconditions include Any authenticated AMQP 0-9-1 client with publish permission can exploit this.. This issue is fixed in versions 4.3.0, 4.2.6, 4.1.11, 4.0.20, and 3.13.15.

## Remediation

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

## Vendor advisories

- **RHSA-2026:67552** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:67552)
- **Red Hat VEX** · Moderate · affected: Red Hat Hardened Images, Red Hat OpenStack Platform 13 (Queens), Red Hat OpenStack Platform 16.2, Red Hat OpenStack Platform 17.1, Red Hat OpenStack Platform 18.0 · no fix planned: Red Hat OpenStack Platform 13 (Queens), Red Hat OpenStack Platform 16.2, Red Hat OpenStack Platform 17.1, Red Hat Hardened Images, … · updated 2026-09-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-67235.json)