# CVE-2026-67412: RabbitMQ: Federation upstream skips vhost authorization allowing cross-vhost message access

CVE-2026-67412 is fixed in rabbitmq-server on 1 platform by DEBIAN-CVE-2026-67412 (version 4.3.6-1), released October 10, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-67412
- Priority: High
- CVSS: 7.1 (Moderate)
- EPSS: 0.0026
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 25, 2026
- Weakness: Missing Authorization
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-67412

## Description

RabbitMQ is a messaging and streaming broker. From 3.13.0 until 4.3.3, 4.2.9 , 4.1.14, 4.0.24, and 3.13.18, Federation upstream in RabbitMQ skips vhost authorization allowing cross-vhost message access. what the bug lets you do. A policymaker on one vhost reads and drains messages out of another vhost it has no permission on. With the default ack-mode the source messages are consumed (deleted), not copied. Why that should not 1. Federation validates the upstream URI without any vhost-access Cross-vhost message read/drain from a per-vhost policymaker, breaking vhost tenancy This issue is fixed in versions 4.3.3, 4.2.9 , 4.1.14, 4.0.24, and 3.13.18.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rabbitmq-server Debian 14 | 4.3.6-1 | [DEBIAN-CVE-2026-67412](https://patchblox.com/security/data/fix/linux/debian-cve-2026-67412.md) | Oct 10, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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