{"id":"CVE-2026-105211","aliases":["EUVD-2026-92104","GHSA-3gwm-5wx8-4gm6","GHSA-mq63-7hcv-jfrc"],"status":"published","title":"ZITADEL before 4.17.1 Authentication Bypass via Login V2 OTP returnCode","description":"ZITADEL before 4.17.1 contains an authentication bypass vulnerability in Login V2 that allows unauthenticated attackers to take over accounts by obtaining OTP codes via the returnCode delivery type. Attackers knowing a login name of a victim with OTP-Email and OTP-SMS enrolled can read both codes from server-action responses to gain MFA-authenticated sessions, including administrator takeover.","severity":{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00333,"percentile":0.26873,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-200"],"published":"2026-10-04T13:10:04Z","modified":"2026-10-28T02:30:46Z","products":[{"vendor":"zitadel","product":"zitadel"}],"references":[{"url":"https://github.com/zitadel/zitadel/security/advisories/GHSA-3gwm-5wx8-4gm6","tags":["vendor-advisory","advisory"]},{"url":"https://www.vulncheck.com/advisories/zitadel-before-4.17.1-authentication-bypass-via-login-v2-otp-returncode","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-105211","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-mq63-7hcv-jfrc"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/105xxx/CVE-2026-105211.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-105211","title":"ZITADEL before 4.17.1 Authentication Bypass via Login V2 OTP returnCode","description":"ZITADEL before 4.17.1 contains an authentication bypass vulnerability in Login V2 that allows unauthenticated attackers to take over accounts by obtaining OTP codes via the returnCode delivery type. Attackers knowing a login name of a victim with OTP-Email and OTP-SMS enrolled can read both codes from server-action responses to gain MFA-authenticated sessions, including administrator takeover.","status":"published","published":"2026-10-04T13:10:04.626Z","modified":"2026-10-05T14:06:56.95Z","cvss":[{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical","assessor":"cna"},{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:19:56.755658Z"}],"euvd":[{"id":"EUVD-2026-92104","description":"ZITADEL before 4.17.1 contains an authentication bypass vulnerability in Login V2 that allows unauthenticated attackers to take over accounts by obtaining OTP codes via the returnCode delivery type. Attackers knowing a login name of a victim with OTP-Email and OTP-SMS enrolled can read both codes from server-action responses to gain MFA-authenticated sessions, including administrator takeover.","status":"published","published":"2026-10-04T13:10:04Z","modified":"2026-10-05T14:06:56Z","cvss":[{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical"}],"updated_at":"2026-11-02T17:27:40.198021Z"}],"ghsa":[{"id":"GHSA-mq63-7hcv-jfrc","title":"ZITADEL before 4.17.1 contains an authentication bypass vulnerability in Login V2 that allows...","description":"ZITADEL before 4.17.1 contains an authentication bypass vulnerability in Login V2 that allows unauthenticated attackers to take over accounts by obtaining OTP codes via the returnCode delivery type. Attackers knowing a login name of a victim with OTP-Email and OTP-SMS enrolled can read both codes from server-action responses to gain MFA-authenticated sessions, including administrator takeover.","status":"published","published":"2026-10-04T15:30:23Z","modified":"2026-10-04T15:30:29Z","cvss":[{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical"},{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T15:12:46.728696Z"}],"nvd":[{"id":"CVE-2026-105211","description":"ZITADEL before 4.17.1 contains an authentication bypass vulnerability in Login V2 that allows unauthenticated attackers to take over accounts by obtaining OTP codes via the returnCode delivery type. Attackers knowing a login name of a victim with OTP-Email and OTP-SMS enrolled can read both codes from server-action responses to gain MFA-authenticated sessions, including administrator takeover.","status":"published","published":"2026-10-04T15:16:32.333Z","modified":"2026-10-05T15:17:19.077Z","cvss":[{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical","assessor":"secondary"},{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:12:53.75133Z"}],"osv":[{"id":"CVE-2026-105211","title":"ZITADEL before 4.17.1 Authentication Bypass via Login V2 OTP returnCode","description":"ZITADEL before 4.17.1 contains an authentication bypass vulnerability in Login V2 that allows unauthenticated attackers to take over accounts by obtaining OTP codes via the returnCode delivery type. Attackers knowing a login name of a victim with OTP-Email and OTP-SMS enrolled can read both codes from server-action responses to gain MFA-authenticated sessions, including administrator takeover.","status":"published","published":"2026-10-04T13:10:04.626Z","modified":"2026-10-28T02:30:46.681329387Z","cvss":[{"version":"4.0","score":9.2,"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"critical"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T15:44:54.583213Z"}]}}