{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "4.3.0"
              },
              {
                "fixed": "4.3.3"
              },
              {
                "introduced": "4.2.0"
              },
              {
                "fixed": "4.2.9"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "1929eeadf9b2bac12c5434fb56884ef27370580e"
            },
            {
              "introduced": "95c501fbad76c66156346cf364d158d6e30aa4d9"
            },
            {
              "fixed": "1d284b2d2a1e2f845ad22b0d5ee38ec372d50802"
            },
            {
              "fixed": "47d6d6457c7d1a440daed643cb7d76bba313e79c"
            },
            {
              "fixed": "a7528314840c4f8dc9904684f9f97ffa7aac6349"
            },
            {
              "fixed": "edbead0eabbd65925d0dc914a22d6a29e155e646"
            }
          ],
          "repo": "https://github.com/rabbitmq/rabbitmq-server",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-4r6f-9cpw-f6g6"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-863"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67411.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "4.1.0"
          },
          {
            "fixed": "4.1.14"
          },
          {
            "introduced": "4.0.0"
          },
          {
            "fixed": "4.0.23"
          },
          {
            "introduced": "3.13.0"
          },
          {
            "fixed": "3.13.18"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3, native MQTT and MQTT over WebSocket behind a trusted PROXY Protocol frontend could lose the proxy-derived client address before the MQTT authentication path checked loopback_users, causing the frontend-to-broker address to be treated as loopback. An attacker who can reach the trusted frontend and has valid credentials for a loopback-restricted account can therefore bypass the source-address restriction; the issue does not bypass password authentication. This issue is fixed in versions 3.13.18, 4.0.23, 4.1.14, 4.2.9, and 4.3.3.",
  "id": "CVE-2026-67411",
  "modified": "2026-09-27T03:30:48.753577215Z",
  "published": "2026-09-25T16:26:33.880Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67411.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-4r6f-9cpw-f6g6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-67411"
    },
    {
      "type": "FIX",
      "url": "https://github.com/rabbitmq/rabbitmq-server/commit/a7528314840c4f8dc9904684f9f97ffa7aac6349"
    },
    {
      "type": "FIX",
      "url": "https://github.com/rabbitmq/rabbitmq-server/commit/edbead0eabbd65925d0dc914a22d6a29e155e646"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "RabbitMQ: Web MQTT with PROXY Protocol enabled: a loopback-only user permission bypass"
}