CVE-2026-105207: Zitadel

Critical severity, CVSS 9.8. EPSS: 0.3% chance of exploitation in the next 30 days.

ZITADEL 3.0.0 through 3.4.15 and 4.0.0 before 4.17.3 creates links between user accounts and external identity providers without verifying a primary factor or the caller's permission, including on identify-only Login V2 sessions and via the User Service V2 AddIDPLink endpoint. An unauthenticated attacker knowing a victim's login name can bind their own external IdP identity to the victim's account and then sign in as the victim.

Affected products

• Zitadel Zitadel: before 4.17.3 (fixed in 4.17.3); up to and including 4.19.4

Published 2026-10-04. Last modified 2026-10-06.