VMware RabbitMQ up to 3.13.14/4.0.19/4.1.10/4.2.5 Management UI connection.ejs rabbit_ssl:peer_cert_subject cross site scripting

Summaryinfo

A vulnerability was found in VMware RabbitMQ up to 3.13.14/4.0.19/4.1.10/4.2.5 and classified as problematic. This affects the function rabbit_ssl:peer_cert_subject of the file connection.ejs of the component Management UI. The manipulation results in cross site scripting. This vulnerability is cataloged as CVE-2026-66077. The attack may be launched remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in VMware RabbitMQ up to 3.13.14/4.0.19/4.1.10/4.2.5. Affected is the function rabbit_ssl:peer_cert_subject of the file connection.ejs of the component Management UI. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6, The management UI uses EJS 1.0 in which <%= ... %> does NOT HTML-escape. connection.ejs:135 renders <%= connection.ssl_details.peer_cert_subject %> (and peer_cert_issuer) directly into the page. The same pattern appears in streamConnection.ejs:102,106,110. The values come from rabbit_ssl:peer_cert_subject/1 which formats the DN as a string without HTML escaping. The verifier corrected the original researcher's claim: this is reachable only when the listener is configured with verify_peer (so the certificate must be signed by a CA in the broker's trust store, not arbitrary self-signed); however, in deployments using mTLS for client authentication, any user who can request a certificate from the organisational CA controls the Subject CN. An attacker who can obtain a TLS client certificate signed by a CA the broker trusts (with verify_peer enabled) can embed JavaScript in the certificate's Subject DN. When any administrator views that connection in the management UI, the script executes in the admin's browser session, allowing full account takeover (create users, export definitions, etc.). The management UI's CSP includes 'unsafe-inline', so inline script execution is not blocked. Preconditions include TLS listener configured with ssl_options.verify = verify_peer Attacker can obtain a CA-signed client certificate with attacker-chosen Subject (e.g. self-service corporate PKI, or rabbitmq_trust_store plugin in use) Administrator views the connection detail page. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-66077 since 07/24/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Additional levels of successful authentication are needed for exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 3.13.15, 4.0.20, 4.1.11 or 4.2.6 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-2268). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Open Source RabbitMQ

Productinfo

Vendor

• VMware

Name

• RabbitMQ

Version

• 3.13.0
• 3.13.1
• 3.13.2
• 3.13.3
• 3.13.4
• 3.13.5
• 3.13.6
• 3.13.7
• 3.13.8
• 3.13.9
• 3.13.10
• 3.13.11
• 3.13.12
• 3.13.13
• 3.13.14
• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3
• 4.0.4
• 4.0.5
• 4.0.6
• 4.0.7
• 4.0.8
• 4.0.9
• 4.0.10
• 4.0.11
• 4.0.12
• 4.0.13
• 4.0.14
• 4.0.15
• 4.0.16
• 4.0.17
• 4.0.18
• 4.0.19
• 4.1.0
• 4.1.1
• 4.1.2
• 4.1.3
• 4.1.4
• 4.1.5
• 4.1.6
• 4.1.7
• 4.1.8
• 4.1.9
• 4.1.10
• 4.2.0
• 4.2.1
• 4.2.2
• 4.2.3
• 4.2.4
• 4.2.5

License

• commercial

Website

• Vendor: https://www.vmware.com/

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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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