CVE-2026-105211 PUBLISHED

ZITADEL before 4.17.1 Authentication Bypass via Login V2 OTP returnCode

Assigner: VulnCheck
Reserved: 04.10.2026 Published: 04.10.2026 Updated: 05.10.2026

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.

CVSS 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
CVSS Score: 9.2

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	High	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 8.1

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	zitadel
Product	zitadel
Versions	Default: unaffected affected from 0 to 4.17.1 (excl.) Version 4.17.1 is unaffected

CVE-2026-105211 PUBLISHED

ZITADEL before 4.17.1 Authentication Bypass via Login V2 OTP returnCode

Metrics

Product Status

Credits

References

Problem Types