{"id":"CVE-2026-67407","state":"PUBLISHED","title":"RabbitMQ: Incomplete fix for CVE-2026-44838: `escape_regex_char/1` does not escape `-`, leaving room for an MQTT topic permission bypass","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.","publishedAt":"2026-09-25T16:30:35.252Z","updatedAt":"2026-09-25T17:20:31.333Z","severity":{"score":5.1,"label":"Medium","version":"4.0","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","source":"GitHub_M"},"assigner":"GitHub_M","products":["rabbitmq rabbitmq-server"],"affected":[{"vendor":"rabbitmq","product":"rabbitmq-server","versions":[{"version":">= 4.3.2, < 4.3.3","status":"affected"},{"version":">= 4.2.0, < 4.2.9","status":"affected"},{"version":">= 4.1.0, < 4.1.14","status":"affected"},{"version":">= 4.0.0, < 4.0.23","status":"affected"}]}],"references":["https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q46v-hrvq-hp24","https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9","https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3"],"weaknesses":["CWE-862"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/67xxx/CVE-2026-67407.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-67407","state":"PUBLISHED","datePublished":"2026-09-25T16:30:35.252Z","dateUpdated":"2026-09-25T17:20:31.333Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-29T15:02:20.411Z"},"containers":{"cna":{"title":"RabbitMQ: Incomplete fix for CVE-2026-44838: `escape_regex_char/1` does not escape `-`, leaving room for an MQTT topic permission bypass","descriptions":[{"lang":"en","value":"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":[{"vendor":"rabbitmq","product":"rabbitmq-server","versions":[{"version":">= 4.3.2, < 4.3.3","status":"affected"},{"version":">= 4.2.0, < 4.2.9","status":"affected"},{"version":">= 4.1.0, < 4.1.14","status":"affected"},{"version":">= 4.0.0, < 4.0.23","status":"affected"}]}],"references":[{"url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q46v-hrvq-hp24","name":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-q46v-hrvq-hp24","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9","name":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9","tags":["x_refsource_MISC"]},{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3","name":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"HIGH","subAvailabilityImpact":"NONE","baseScore":5.1,"baseSeverity":"MEDIUM","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-862","lang":"en","description":"CWE-862: Missing Authorization","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-25T16:30:35.252Z"},"source":{"advisory":"GHSA-q46v-hrvq-hp24","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-25T17:20:18.793859Z","id":"CVE-2026-67407","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-25T17:20:31.333Z"}}]}}}