{"schemaVersion":3,"id":"CVE-2026-67407","aliases":["UBUNTU-CVE-2026-67407","DEBIAN-CVE-2026-67407"],"status":"published","duplicateOf":null,"title":null,"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.","dates":{"published":"2026-09-25T16:30:35.252Z","modified":"2026-09-25T17:20:31.333Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.1,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"NVD","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","computed":false,"selection":"backend-summary"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"CVE.org","score":5.1,"severity":"medium","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N","exploitability":null,"impact":null,"computed":false},{"version":"4.0","versionLabel":"v4.0","source":"OSV · 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