ZITADEL up to 4.16.0 Login V2 improper authentication

Summaryinfo

A vulnerability was found in ZITADEL up to 4.16.0. It has been classified as critical. The affected element is an unknown function of the component Login V2. Performing a manipulation results in improper authentication. This vulnerability is identified as CVE-2026-85056. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as critical, was found in ZITADEL up to 4.16.0. This affects an unknown code block of the component Login V2. The manipulation with an unknown input leads to a improper authentication vulnerability. CWE is classifying the issue as CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

ZITADEL is an open source identity management platform. From 4.0.0 until 4.16.1, ZITADEL Login V2 creates a browser session after password verification and can reuse that session for a later authentication request without verifying a user's enrolled TOTP, OTP, or U2F second factor. When the MFA step is abandoned and login starts again, session-validity checks require MFA only when the organization enables Force MFA or Force MFA for local users only, so a voluntarily enrolled factor can be skipped while completing an OIDC or SAML callback for a customer application. Login V1, the ZITADEL Console, Management and Admin APIs, and user self-management are not affected. This issue is fixed in version 4.16.1.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-85056 since 09/02/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available.

Upgrading to version 4.16.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-86324). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• ZITADEL

Version

• 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
• 4.16.0

Website

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

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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