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

Medium · CVSS 5.3CVE-2026-67405

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

Answer in brief

CVE-2026-67405 records a Medium severity (CVSS 5.3) vulnerability in RabbitMQ: CSWSH on Web-STOMP / Web-MQTT (no Origin validation). The current sources do not mark it as known exploited. The current feed maps rabbitmq/rabbitmq-server (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 23, 2026Updated Sep 23, 2026Source checked Sep 24, 2026First seen by HOL Sep 23, 2026Material review Sep 23, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps rabbitmq/rabbitmq-server (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
rabbitmq/rabbitmq-servergeneric	>=3.13.0 <3.13.15 \|\| >=4.0.0 <4.0.20 \|\| >=4.1.0 <4.1.11 \|\| >=4.2.0 <4.2.6	3.13.15, 4.0.20, 4.1.11, 4.2.6

Recommended response

Check inventory. Check lockfiles and deployed manifests for rabbitmq/rabbitmq-server.
Review the reported fix. Update rabbitmq/rabbitmq-server to 3.13.15 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 23, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 23, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.