OCTOBER 10, 2026
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Case File

CVE-2026-66077

HIGH · CVSS 7.3 EPSS 0.30% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-09-23 · Last synced 2026-10-10

CyberRota Analysis

AI-Generated

The RabbitMQ management UI is vulnerable due to improper HTML escaping in the rendering of TLS client certificate details, allowing an attacker with a CA-signed client certificate to inject malicious JavaScript. This can lead to full account takeover when an administrator views the affected connection details, as the management UI's content security policy permits inline script execution. Organizations using RabbitMQ with mTLS for client authentication should prioritize patching to versions 3.13.15, 4.0.20, 4.1.11, or 4.2.6 to mitigate this risk.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-66077
Severity
HIGH
CVSS
7.3
EPSS
0.30%
Java

Original NVD Description

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.