CVE-2026-67405 RabbitMQ: CSWSH on Web-STOMP / Web-MQTT (no Origin validation)

Medium 5.3 Published Updated

Attackers can hijack user sessions via Cross-Site WebSocket Hijacking in RabbitMQ Web-STOMP/MQTT plugins when specific authentication settings are enabled.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2026-67405?

CVE-2026-67405 is a medium-severity vulnerability in Broadcom Rabbitmq Server, published on 23 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0, Neither the Web-MQTT handler (deps/rabbitmq_web_mqtt/src/rabbit_web_mqtt_handler.erl:104) nor the Web-STOMP handler (deps/rabbitmq_web_stomp/src/rabbit_web_stomp_handler.erl:102) validates the Origin header on the WebSocket upgrade. Under ssl_cert_login=true, the browser presents the client certificate automatically, so an attacker's JavaScript running in the victim's browser can authenticate as the victim. Preconditions include The non-default configuration use_http_auth=true (Web-STOMP) or ssl_cert_login=true (both plugins) must be enabled. The issue is harmless under the default in-band CONNECT credential configuration.. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, 4.2.6, and 4.3.0.

Weakness: CWE-1385

Which versions are affected by CVE-2026-67405?

1 open source package ship an affected version, including rabbitmq. It affects 1 product.

PackageAffectedFixed in
rabbitmq BitnamiFrom 3.13.03.13.15, 4.0.20, 4.1.11, 4.2.6

Products include Broadcom Rabbitmq Server.

How do I fix CVE-2026-67405?

Upgrade rabbitmq to a fixed version for your release line: 3.13.15, 4.0.20, 4.1.11 or 4.2.6.

Is CVE-2026-67405 being exploited?

There is no known exploitation of CVE-2026-67405 in the wild and no public exploit code.

All Broadcom Rabbitmq Server vulnerabilities

Sources

Also known as AZL-105747, BIT-rabbitmq-2026-67405, DEBIAN-CVE-2026-67405, GHSA-9c4f-rxxm-88q3, UBUNTU-CVE-2026-67405.

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