{"id":"CVE-2026-105211","published":"2026-10-04T15:16:32.333","lastModified":"2026-10-05T15:17:19.077","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.","cvssScore":8.1,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","cwes":["CWE-200"],"vendors":[],"products":[],"references":[{"url":"https://github.com/zitadel/zitadel/security/advisories/GHSA-3gwm-5wx8-4gm6","tags":[]},{"url":"https://www.vulncheck.com/advisories/zitadel-before-4.17.1-authentication-bypass-via-login-v2-otp-returncode","tags":[]}],"exploitRefs":[{"url":"https://github.com/zitadel/zitadel/security/advisories/GHSA-3gwm-5wx8-4gm6","tags":[]}],"hasPoc":true,"ai":{"summary":"This vulnerability allows unauthenticated attackers to bypass authentication by obtaining OTP codes, potentially taking over accounts and gaining MFA-authenticated sessions, including administrator access.","exploitability":"Exploitation requires knowledge of a victim's login name and access to server-action responses, making it moderately difficult.","blast_radius":"If exploited, the impact could be severe, as it allows attackers to take over accounts and gain full access, including administrative privileges.","remediation":"Upgrade to ZITADEL 4.17.1 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["auth-bypass","mfa","otp","web"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-10-06T08:45:32.227Z"}}