{"cve":"CVE-2021-3754","nvd":{"published":"2022-08-26T16:15:09.520","modified":"2026-06-17T04:05:42.230","status":"Modified","description":"A flaw was found in keycloak where an attacker is able to register himself with the username same as the email ID of any existing user. This may cause trouble in getting password recovery email in case the user forgets the password.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","score":5.3},"cwes":["CWE-20"],"references":["https://access.redhat.com/security/cve/CVE-2021-3754","https://bugzilla.redhat.com/show_bug.cgi?id=1999196","https://access.redhat.com/security/cve/CVE-2021-3754","https://bugzilla.redhat.com/show_bug.cgi?id=1999196"],"products":["redhat:keycloak","redhat:single_sign-on"],"source":"nvd","synced_at":"2026-10-19T21:35:14.992143698+00:00"},"epss":{"cve":"CVE-2021-3754","score":0.02194,"percentile":0.82467,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-4vc8-pg5c-vg4x","url":"https://osv.dev/vulnerability/GHSA-4vc8-pg5c-vg4x","summary":"Keycloak's improper input validation allows using email as username","modified":"2024-12-20T18:26:47.874361Z","packages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","purl":"pkg:maven/org.keycloak/keycloak-services","ranges":["<24.0.1"],"fixed":["24.0.1"]}]}],"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."]}