{"id":"CVE-2026-67407","title":"RabbitMQ is a messaging and streaming broker","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-…","severity":"medium","cvss":5.1,"cvssVector":"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","cwe":["CWE-862"],"vendor":"rabbitmq","product":"rabbitmq-server","affected":["rabbitmq-server >= 4.3.2, < 4.3.3","rabbitmq-server >= 4.2.0, < 4.2.9","rabbitmq-server >= 4.1.0, < 4.1.14","rabbitmq-server >= 4.0.0, < 4.0.23"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T18:17:30.073","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-67407","references":[{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9","label":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3","label":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q46v-hrvq-hp24","label":"security-advisories@github.com"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-25T17:20:18.793859Z"},"cvssSource":"cna","ingestedAt":"2026-09-25T17:13:14.022Z","slug":"CVE-2026-67407","body":"## Overview\n\nRabbitMQ 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":28,"depthScoreParts":{"impact":28.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}