Medium 5.3Published Sep 23, 2026

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

Updated under an hour ago (2026-10-19 09:00 UTC)

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It affects rabbitmq-server. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 5.3 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
Weakness (CWE): CWE-1385
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Undergoing Analysis
Record last updated: Sep 24, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

rabbitmq rabbitmq-server rabbitmq:server (from the name)	from 3.13.0, < 3.13.15; from 4.0.0, < 4.0.20; from 4.1.0, < 4.1.11; from 4.2.0, < 4.2.6	CNA record

References

https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-9c4f-rxxm-88q3x-refsource-confirm
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6x-refsource-misc
https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.0x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.