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.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

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

cve-icon OpenCVE Enrichment

Updated: 2026-09-24T01:30:12Z

Weaknesses