{"id":"CVE-2026-66067","published":"2026-09-23T21:16:58.783","lastModified":"2026-09-24T15:02:58.307","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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-770"],"vendors":[],"products":[],"references":[{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.7","tags":[]},{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1","tags":[]},{"url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-hwqx-2gfg-89qf","tags":[]}],"exploitRefs":[{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.7","tags":[]},{"url":"https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.1","tags":[]},{"url":"https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-hwqx-2gfg-89qf","tags":[]}],"hasPoc":true,"ai":null}