CVE-2026-67412
Published:September 25, 2026
Updated:October 09, 2026
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.
Affected Packages
rabbitmq-server (CONDA):
Affected version(s) >=4.3.1 <4.3.4Fix Suggestion:
Update to version 4.3.4https://github.com/rabbitmq/rabbitmq-server.git (GITHUB):
Affected version(s) >=v4.2.0-beta.1 <v4.2.9Fix Suggestion:
Update to version v4.2.9https://github.com/rabbitmq/rabbitmq-server.git (GITHUB):
Affected version(s) >=v4.3.0-beta.1 <v4.3.3Fix Suggestion:
Update to version v4.3.3Related Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
6
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.7
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Missing Authorization
EPSS
Base Score:
0.30