CVE-2026-105215: Zitadel

Critical severity, CVSS 9.1. EPSS: 0.3% chance of exploitation in the next 30 days.

ZITADEL before 3.4.14 and 4.x before 4.16.2 contains an authentication bypass in the hosted Login V1 UI because the 'external account not found' registration endpoint trusts client-supplied external identity fields without a completed IdP callback. Unauthenticated attackers can submit forged IDPConfigID and ExternalUserID values to pre-create an account bound to a victim's external IdP identity, which the victim's later genuine external login then signs into.

Affected products

• Zitadel Zitadel: before 4.16.2 (fixed in 4.16.2); before 3.4.14 (fixed in 3.4.14)

Published 2026-10-04. Last modified 2026-10-05.