What’s Vulnerable › Vulnerabilities

CVE-2026-105210: ZITADEL before 4.17.1 Unauthenticated MFA Enrollment via Login V1 Init Handlers

• Severity: high (CVSS 8.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-04 · updated 2026-10-29
• Weakness: CWE-287

Description

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.

Affected products

• zitadel: from 4.0.0 before 4.17.1 — fixed in 4.17.1

How to fix

Upgrade to a fixed version: zitadel 4.17.1. Check the vendor advisory for mitigations.

References

• https://github.com/zitadel/zitadel/security/advisories/GHSA-72q5-mv5c-vxv4
• https://www.vulncheck.com/advisories/zitadel-before-4.17.1-unauthenticated-mfa-enrollment-via-login-v1-init-handlers

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