{"id":"CVE-2026-105215","published":"2026-10-04T15:16:32.993","lastModified":"2026-10-05T14:17:18.137","description":"ZITADEL before 3.4.14 and 4.x before 4.16.2 contains an authentication bypass in the hosted Login V1 UI because the 'external account not found' registration endpoint trusts client-supplied external identity fields without a completed IdP callback. Unauthenticated attackers can submit forged IDPConfigID and ExternalUserID values to pre-create an account bound to a victim's external IdP identity, which the victim's later genuine external login then signs into.","cvssScore":9.1,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","cwes":["CWE-290"],"vendors":[],"products":[],"references":[{"url":"https://github.com/zitadel/zitadel/security/advisories/GHSA-738m-7888-jfv8","tags":[]},{"url":"https://www.vulncheck.com/advisories/zitadel-before-4.16.2-account-pre-hijacking-via-forged-external-idp-callback","tags":[]}],"exploitRefs":[{"url":"https://github.com/zitadel/zitadel/security/advisories/GHSA-738m-7888-jfv8","tags":[]}],"hasPoc":true,"ai":{"summary":"The flaw allows unauthenticated attackers to bypass authentication by pre-creating an account using forged external identity fields, posing a significant security risk.","exploitability":"Exploitation is relatively easy as it requires submitting forged IDPConfigID and ExternalUserID values without a completed IdP callback.","blast_radius":"If exploited, this could lead to unauthorized access to sensitive systems and data, compromising user accounts and potentially the entire system.","remediation":"Upgrade to ZITADEL 3.4.14 or 4.16.2 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["auth-bypass","web","external-identity","unauthenticated"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-10-05T08:42:24.929Z"}}