Vulnerability Description
RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.3.3 and 4.2.9 and 4.1.14 and 4.0.23, Incomplete fix for CVE-2026-44838: escaperegexchar/1 does not escape -, leaving room for an MQTT topic permission bypass. the CVE-2026-44838 fix made expandtopicpermission/2 escape regex metacharacters in expanded topic-permission variables (escaperegex(V)), but escaperegexchar/1 escapes \ ^ $ . | ? + ( ) [ ] { } and omits -. When a topic permission template places {clientid} inside a [...] character class A low-privileged authenticated MQTT user controlling its clientid can broaden topic authorization (read and write) when templates embed {clientid} in a [...] This issue is fixed in versions 4.3.3 and 4.2.9 and 4.1.14 and 4.0.23.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Broadcom | Rabbitmq Server | >= 4.0.0, < 4.0.23 |
Related Weaknesses (CWE)
References
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9Release Notes
- https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3Release Notes
- https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q46v-hrvq-hVendor AdvisoryExploitMitigation
FAQ
What is CVE-2026-67407?
CVE-2026-67407 is a vulnerability with a CVSS score of 7.1 (HIGH). RabbitMQ is a messaging and streaming broker. From 4.0.0 until 4.3.3 and 4.2.9 and 4.1.14 and 4.0.23, Incomplete fix for CVE-2026-44838: escaperegexchar/1 does not escape -, leaving room for an MQTT t...
How severe is CVE-2026-67407?
CVE-2026-67407 has been rated HIGH with a CVSS base score of 7.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-67407?
Check the references section above for vendor advisories and patch information. Affected products include: Broadcom Rabbitmq Server.