CVE-2026-66067

Medium

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.

SeverityMedium
CVSS6.0
Exploit probability—
ProductBroadcom Rabbitmq Server
PublishedSep 23, 2026
First seenSep 23, 2026

How to fix

Update
  • broadcom rabbitmq_server4.2.7, 4.3.1 or later

Affected products

ProductAffected versionsFixed in
broadcom rabbitmq_server4.2.0 ≤ v < 4.2.7, 4.3.0 ≤ v < 4.3.14.2.7, 4.3.1

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CVE-2026-66067 · Broadcom Rabbitmq Server · Dark Radar