{"cve":"CVE-2021-3827","nvd":{"published":"2022-08-23T16:15:10.030","modified":"2026-06-17T04:05:50.910","status":"Modified","description":"A flaw was found in keycloak, where the default ECP binding flow allows other authentication flows to be bypassed. By exploiting this behavior, an attacker can bypass the MFA authentication by sending a SOAP request with an AuthnRequest and Authorization header with the user's credentials. The highest threat from this vulnerability is to confidentiality and integrity.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N","score":6.8},"cwes":["CWE-287"],"references":["https://access.redhat.com/security/cve/CVE-2021-3827","https://bugzilla.redhat.com/show_bug.cgi?id=2007512","https://github.com/keycloak/keycloak/commit/44000caaf5051d7f218d1ad79573bd3d175cad0d","https://github.com/keycloak/keycloak/security/advisories/GHSA-4pc7-vqv5-5r3v","https://access.redhat.com/security/cve/CVE-2021-3827"],"products":["redhat:keycloak","redhat:openshift_container_platform","redhat:single_sign-on"],"source":"nvd","synced_at":"2026-10-19T21:34:18.502168378+00:00"},"epss":{"cve":"CVE-2021-3827","score":0.0111,"percentile":0.65934,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-4pc7-vqv5-5r3v","url":"https://osv.dev/vulnerability/GHSA-4pc7-vqv5-5r3v","summary":"ECP SAML binding bypasses authentication flows","modified":"2026-07-08T06:30:00.191333230Z","packages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-saml-core","purl":"pkg:maven/org.keycloak/keycloak-saml-core","ranges":["<18.0.0"],"fixed":["18.0.0"]}]}],"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."]}