CVE-2026-67407

Summary

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.

Affected Software

VendorProductVersion RangeStatus
rabbitmqrabbitmq-server>= 4.3.2, < 4.3.3affected
rabbitmqrabbitmq-server>= 4.2.0, < 4.2.9affected
rabbitmqrabbitmq-server>= 4.1.0, < 4.1.14affected
rabbitmqrabbitmq-server>= 4.0.0, < 4.0.23affected

Weaknesses

  • CWE-862: CWE-862: Missing Authorization

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References