{"cve":"CVE-2021-4133","nvd":{"published":"2022-01-25T20:15:08.607","modified":"2026-06-17T04:19:05.610","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-863"],"references":["https://bugzilla.redhat.com/show_bug.cgi?id=2033602","https://github.com/keycloak/keycloak/issues/9247","https://github.com/keycloak/keycloak/security/advisories/GHSA-83x4-9cwr-5487","https://www.oracle.com/security-alerts/cpuapr2022.html","https://bugzilla.redhat.com/show_bug.cgi?id=2033602"],"products":["redhat:keycloak"],"source":"nvd","synced_at":"2026-10-19T21:27:20.926095847+00:00"},"epss":{"cve":"CVE-2021-4133","score":0.01373,"percentile":0.71995,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-83x4-9cwr-5487","url":"https://osv.dev/vulnerability/GHSA-83x4-9cwr-5487","summary":"Improper Authorization in Keycloak","modified":"2026-07-16T03:59:28.131012483Z","packages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","purl":"pkg:maven/org.keycloak/keycloak-services","ranges":["<15.1.1"],"fixed":["15.1.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}