{"id":"CVE-2026-66067","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-66067","generatedAt":"2026-10-27T23:57:03.334Z","title":"An authenticated tenant can fully bypass operator-configured per-user and per-vhost connection caps by connecting via port 5552 instead of 5672.","description":"RabbitMQ is a messaging and streaming broker. Prior to versions 4.2.7 and 4.3.1, The stream open handler calls only check_vhost_access; it omits the node/vhost/user connection-limit checks that rabbit_reader performs for AMQP. A developer %% FIXME comment at the cited line explicitly acknowledges the gap. No compensating enforcement exists in connection tracking or elsewhere in rabbitmq_stream. An authenticated tenant can fully bypass operator-configured per-user and per-vhost connection caps by connecting via port 5552 instead of 5672. Preconditions include rabbitmq_stream plugin enabled Authenticated stream-protocol credentials Operator relies on per-user/per-vhost connection limits for tenant isolation. This issue is fixed in versions 4.2.7 and 4.3.1.","published":"2026-09-23T21:16:59.000Z","lastModified":"2026-09-24T15:02:58.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":6,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-770"],"affected":[],"epss":{"score":0.00351,"percentile":0.28521,"date":"2026-10-26","history":[{"date":"2026-09-24","score":0.00351,"percentile":0.25959}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.35%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-23T21:16:59.000Z","detail":{"score":"6.0","severity":"MEDIUM","publishedAt":"2026-09-23T21:16:58.783Z"},"summary":"New CVE, medium severity (CVSS 6.0)."}],"references":[{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.7","source":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1","source":"security-advisories@github.com"},{"url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-hwqx-2gfg-89qf","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-66067","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}