{"id":"CVE-2026-66067","summary":"RabbitMQ: Stream protocol skips per vhost per user connection limits","details":"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.","aliases":["GHSA-hwqx-2gfg-89qf"],"modified":"2026-09-24T11:45:19.128819091Z","published":"2026-09-23T20:12:00.076Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-770"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66067.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66067.json"},{"type":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.7"},{"type":"WEB","url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1"},{"type":"ADVISORY","url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-hwqx-2gfg-89qf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66067"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/rabbitmq/rabbitmq-server","events":[{"introduced":"95c501fbad76c66156346cf364d158d6e30aa4d9"},{"fixed":"b15fd2a3e5465cb6ed403d5a774ef61b1a391b89"},{"introduced":"1929eeadf9b2bac12c5434fb56884ef27370580e"},{"fixed":"49decca35e59d2cb774e5abd76412cee721308a5"}],"database_specific":{"extracted_events":[{"introduced":"4.2.0"},{"fixed":"4.2.7"},{"introduced":"4.3.0"},{"fixed":"4.3.1"}],"source":"AFFECTED_FIELD"}}],"versions":["v4.2.6","v4.3.0","v4.2.5","v4.2.4","v4.2.3","v4.2.2","v4.2.1","v4.2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66067.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}