{
  "cveId": "CVE-2026-66077",
  "url": "https://patchblox.com/security/cve/CVE-2026-66077",
  "summary": "CVE-2026-66077 is fixed in rabbitmq-server on 1 platform, first by rabbitmq-server 4.0.5-10ubuntu5.2, released September 25, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "RabbitMQ: Stored XSS via TLS peer-certificate DN in management UI",
  "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 \u0026lt;%= ... %\u0026gt; does NOT HTML-escape. connection.ejs:135 renders \u0026lt;%= connection.ssl_details.peer_cert_subject %\u0026gt; (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\u0027s 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\u0027s 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\u0027s Subject DN. When any administrator views that connection in the management UI, the script executes in the admin\u0027s browser session, allowing full account takeover (create users, export definitions, etc.). The management UI\u0027s CSP includes \u0027unsafe-inline\u0027, 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.",
  "published": "2026-09-23T14:16:00Z",
  "severity": "Important",
  "cvss": 6.1,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
  "cwe": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
  "epss": 0.00151,
  "epssPercentile": 0.04267,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66077",
  "fixes": [
    {
      "platform": "linux",
      "product": "rabbitmq-server",
      "release": "Debian 14",
      "fixedVersion": "4.3.0-2",
      "fix": "DEBIAN-CVE-2026-66077",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-66077",
      "released": "2026-09-25T19:41:43Z"
    },
    {
      "platform": "linux",
      "product": "rabbitmq-server",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.6.10-1ubuntu0.5\u002Besm1",
      "fix": "rabbitmq-server 3.6.10-1ubuntu0.5\u002Besm1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-rabbitmq-server-3.6.10-1ubuntu0.5-esm1",
      "released": "2026-10-19T16:27:57Z"
    },
    {
      "platform": "linux",
      "product": "rabbitmq-server",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.8.3-0ubuntu0.3\u002Besm2",
      "fix": "rabbitmq-server 3.8.3-0ubuntu0.3\u002Besm2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-rabbitmq-server-3.8.3-0ubuntu0.3-esm2",
      "released": "2026-10-19T16:28:02Z"
    },
    {
      "platform": "linux",
      "product": "rabbitmq-server",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "3.9.27-0ubuntu0.6",
      "fix": "rabbitmq-server 3.9.27-0ubuntu0.6",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-rabbitmq-server-3.9.27-0ubuntu0.6",
      "released": "2026-10-19T16:28:05Z"
    },
    {
      "platform": "linux",
      "product": "rabbitmq-server",
      "release": "Ubuntu 24.04.5 LTS (noble)",
      "fixedVersion": "3.12.1-1ubuntu1.7",
      "fix": "rabbitmq-server 3.12.1-1ubuntu1.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-noble-rabbitmq-server-3.12.1-1ubuntu1.7",
      "released": "2026-10-19T16:28:08Z"
    },
    {
      "platform": "linux",
      "product": "rabbitmq-server",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "4.0.5-10ubuntu5.2",
      "fix": "rabbitmq-server 4.0.5-10ubuntu5.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-rabbitmq-server-4.0.5-10ubuntu5.2",
      "released": "2026-09-25T10:17:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}