{"cve":"CVE-2026-4633","nvd":{"published":"2026-03-23T11:16:25.053","modified":"2026-10-22T22:18:07.123","status":"Modified","description":"A flaw was found in Keycloak. A remote attacker can exploit differential error messages during the identity-first login flow when Organizations are enabled. This vulnerability allows an attacker to determine the existence of users, leading to information disclosure through user enumeration.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","score":3.7},"cwes":["CWE-209"],"references":["https://access.redhat.com/errata/RHSA-2026:19596","https://access.redhat.com/security/cve/CVE-2026-4633","https://bugzilla.redhat.com/show_bug.cgi?id=2450247"],"products":["redhat:build_of_keycloak"],"source":"nvd","synced_at":"2026-10-23T16:39:26.291718493+00:00"},"epss":{"cve":"CVE-2026-4633","score":0.00422,"percentile":0.36249,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-rhgq-f8x5-j2jc","url":"https://osv.dev/vulnerability/GHSA-rhgq-f8x5-j2jc","summary":"Keycloak's identity-first login flow exposes user information","modified":"2026-10-23T00:45:08.239504616Z","packages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","purl":"pkg:maven/org.keycloak/keycloak-services","ranges":[">=26.5.0 <26.6.1"],"fixed":["26.6.1"]},{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","purl":"pkg:maven/org.keycloak/keycloak-services","ranges":["<26.4.12"],"fixed":["26.4.12"]}]}],"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."]}