High severity · published Sep 25, 2026
CVE-2026-67412
RabbitMQ: Federation upstream skips vhost authorization allowing cross-vhost message access
7.1
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 18% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RA
rabbitmq-server · rabbitmq
>= 4.3.0, < 4.3.3; >= 4.2.0, < 4.2.9; >= 4.1.0, < 4.1.14; >= 4.0.0, < 4.0.24; >= 3.13.0, < 3.13.18 · source: vendor
RS
Rabbitmq Server · Broadcom
3.13.0 before 3.13.18; 4.0.0 before 4.0.24; 4.1.0 before 4.1.14; 4.2.0 before 4.2.9; 4.3.0 before 4.3.3 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-67412
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-67412
Release Notes
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9
Release Notes
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3
Exploit
https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-42pc-678q-v8qj
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