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.
History

Fri, 25 Sep 2026 05:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 24 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1220
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Wed, 23 Sep 2026 23:00:00 +0000

Type Values Removed Values Added
First Time appeared Rabbitmq
Rabbitmq rabbitmq-server
Vendors & Products Rabbitmq
Rabbitmq rabbitmq-server

Wed, 23 Sep 2026 20:30:00 +0000

Type Values Removed Values Added
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.
Title RabbitMQ: Stream protocol skips per vhost per user connection limits
Weaknesses CWE-770
References
Metrics cvssV4_0

{'score': 6, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-09-23T20:12:00.076Z

Updated: 2026-09-24T14:11:44.566Z

Reserved: 2026-07-23T23:25:28.897Z

Link: CVE-2026-66067

cve-icon Vulnrichment

Updated: 2026-09-24T14:11:37.335Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-23T21:16:58.783

Modified: 2026-09-24T15:02:58.307

Link: CVE-2026-66067

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-23T20:12:00Z

Links: CVE-2026-66067 - Bugzilla