Zitadel up to 3.4.14/4.17.0 Login V1 UI missing authentication

Summaryinfo

A vulnerability identified as critical has been detected in Zitadel up to 3.4.14/4.17.0. This affects an unknown function of the component Login V1 UI. This manipulation causes missing authentication. This vulnerability appears as CVE-2026-105210. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Zitadel up to 3.4.14/4.17.0. Affected by this vulnerability is some unknown functionality of the component Login V1 UI. The manipulation with an unknown input leads to a missing authentication vulnerability. The CWE definition for the vulnerability is CWE-306. The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

ZITADEL 3.x before 3.4.15 and 4.x before 4.17.1 contains a missing authentication flaw in the hosted Login V1 UI, whose second-factor enrollment and initialization handlers act on an identify-only session before any primary factor is verified. Attackers knowing only a victim's login name can enroll attacker-controlled TOTP, OTP-SMS, OTP-Email, or U2F factors, overwrite the verified phone number, and enumerate users through discrepant errors.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-105210 since 10/04/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 3.4.15 or 4.17.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-92103). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• Zitadel

Version

• 3.4.0
• 3.4.1
• 3.4.2
• 3.4.3
• 3.4.4
• 3.4.5
• 3.4.6
• 3.4.7
• 3.4.8
• 3.4.9
• 3.4.10
• 3.4.11
• 3.4.12
• 3.4.13
• 3.4.14
• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17.0

Website

• Product: https://github.com/zitadel/zitadel/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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