{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "2.12.0"
              },
              {
                "fixed": "2.12.12"
              },
              {
                "introduced": "2.14.0"
              },
              {
                "fixed": "2.14.3"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "fc6ec648d806652d282d2f0edb6cb9f22c895572"
            },
            {
              "fixed": "e8de2a67c7a094abca6013931ecf6cbff4b3fb02"
            },
            {
              "introduced": "0cbd01caf8f29011c26273ff7662addd3830396a"
            },
            {
              "fixed": "9b17a586be69c9ff36e4c84a421ca47da410b561"
            }
          ],
          "repo": "https://github.com/nats-io/nats-server",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-hmmp-q8cx-v964"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-863"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/58xxx/CVE-2026-58211.json"
  },
  "details": "NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, a client could be registered as the configured no_auth_user through a parser path used when the first client operation was not CONNECT, bypassing user-level connection restrictions such as allowed_connection_types or proxy_required that normal authentication would apply. This issue is fixed in versions 2.14.3 and 2.12.12.",
  "id": "CVE-2026-58211",
  "modified": "2026-08-12T03:51:28.386378529Z",
  "published": "2026-07-08T20:16:25.262Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/58xxx/CVE-2026-58211.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/nats-io/nats-server/security/advisories/GHSA-hmmp-q8cx-v964"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-58211"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "NATS Server: `no_auth_user` pre-CONNECT fast path bypasses user connection restrictions"
}