{"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":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","cwe":["CWE-862","CWE-184"],"vendor":"broadcom","product":"rabbitmq_server","affected":["rabbitmq_server >= 4.0.0, < 4.0.23","rabbitmq_server >= 4.1.0, < 4.1.14","rabbitmq_server >= 4.2.0, < 4.2.9","rabbitmq_server >= 4.3.0, < 4.3.3"],"patched":["rabbitmq_server 4.3.3"],"published":"2026-09-25","updated":"2026-10-16","sourceUpdated":"2026-10-16T16:10:40.583","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"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-67407.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-67407"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541524"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-67407"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-67407"},{"url":"https://access.redhat.com/errata/RHSA-2026:67552"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00263,"epssPercentile":0.18039,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-25T17:20:18.793859Z"},"scores":{"nvd":7.1,"cna":5.1,"vendor":4.2},"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## Affected\n\n- `rabbitmq_server >= 4.0.0, < 4.0.23`\n- `rabbitmq_server >= 4.1.0, < 4.1.14`\n- `rabbitmq_server >= 4.2.0, < 4.2.9`\n- `rabbitmq_server >= 4.3.0, < 4.3.3`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `rabbitmq_server 4.3.3`\n\n## Vendor advisories\n\n- **RHSA-2026:67552** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:67552)\n- **Red Hat VEX** · Moderate · affected: Red Hat Hardened Images, Red Hat OpenStack Platform 13 (Queens), Red Hat OpenStack Platform 16.2, Red Hat OpenStack Platform 17.1, Red Hat OpenStack Platform 18.0 · no fix planned: Red Hat OpenStack Platform 13 (Queens), Red Hat OpenStack Platform 16.2, Red Hat OpenStack Platform 17.1, Red Hat Hardened Images, … · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-67407.json)","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":230356,"id":"CVE-2026-67407","ts":1793130920177,"field":"cvss","old":"5.1","new":"7.1"},{"seq":230355,"id":"CVE-2026-67407","ts":1793130920177,"field":"severity","old":"medium","new":"high"}]}