CVE-2026-105211

HIGH 8.1

ZITADEL before 4.17.1 Authentication Bypass via Login V2 OTP returnCode

CVSS Score

8.1

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-200
Vendor	zitadel
Product	zitadel
Published	Oct 4, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

zitadel / zitadel

0 < 4.17.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/zitadel/zitadel/security/advisories/GHSA-3gwm-5wx8-4gm6 vulncheck.com: https://www.vulncheck.com/advisories/zitadel-before-4.17.1-authentication-bypass-via-login-v2-otp-returncode

Credits

IAM-marco livio-a 🔍 lucasdodgson