Messaging and Streaming Broker Vulnerability in RabbitMQ
CVE-2026-67407

5.1MEDIUM

Key Information:

Vendor

RabbitMQ

Status
RabbitMQ-server
Vendor
CVE Published:
25 September 2026

What is CVE-2026-67407?

An incomplete fix in RabbitMQ versions 4.0.0 to 4.3.3 allows low-privileged authenticated MQTT users to bypass topic permissions. Specifically, the escaperegexchar/1 function fails to escape the hyphen (‘-’), potentially enabling unauthorized access to broadened topic authorization when templates include {clientid} within variable classes. The issue is mitigated in later versions 4.3.3, 4.2.9, 4.1.14, and 4.0.23.

Affected Version(s)

rabbitmq-server >= 4.3.2, < 4.3.3 < 4.3.2, 4.3.3

rabbitmq-server >= 4.2.0, < 4.2.9 < 4.2.0, 4.2.9

rabbitmq-server >= 4.1.0, < 4.1.14 < 4.1.0, 4.1.14

References

https://github.com/rabbitmq/rabbitmq-server/security/advi...
x_refsource_CONFIRM
https://github.com/rabbitmq/rabbitmq-server/releases/tag/...
x_refsource_MISC
https://github.com/rabbitmq/rabbitmq-server/releases/tag/...
x_refsource_MISC

CVSS V4

Score:
5.1
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.