Security advisory

{
  "id": "9dd77e31f050de10493743534225035ddc74c7becbd90171ac03c98d8ed792d3",
  "url": "https://osv.dev/vulnerability/CVE-2021-4133",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-4133",
    "summary": "A flaw was found in Keycloak in versions from 12.0.0 and before 15.1.1 which allows an attacker with any existing user account to create new default user accounts via the administrative REST API even when new user registration is disabled.",
    "evidence": "osv:CVE-2021-4133",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-4133",
      "aliases": [
        "CVE-2021-4133",
        "GHSA-83x4-9cwr-5487"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/keycloak/keycloak",
              "type": "GIT",
              "events": [
                {
                  "introduced": "2690229863ddbcdfa2c75e00a7a9858e2e03c6c9"
                },
                {
                  "fixed": "6bfd4549bb1e9a17791849252e1de0d95a9f4012"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:redhat:keycloak:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "12.0.0"
                      },
                      {
                        "fixed": "15.1.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-4133.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:58.369898863Z",
      "provider": "osv",
      "references": [
        "https://www.oracle.com/security-alerts/cpuapr2022.html",
        "https://github.com/keycloak/keycloak/issues/9247",
        "https://github.com/keycloak/keycloak/security/advisories/GHSA-83x4-9cwr-5487",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2033602"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-4133",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 386596,
  "published_at": "2022-01-25T20:15:08.607+00:00"
}