CVE-2026-34727: Vikunja has TOTP Two-Factor Authentication Bypass via OIDC Login Path

Severity: Critical

CVSS Score: 7.4

Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the OIDC callback handler issues a full JWT token without checking whether the matched user has TOTP two-factor authentication enabled. When a local user with TOTP enrolled is matched via the OIDC email fallback mechanism, the second factor is completely skipped. This vulnerability is fixed in 2.3.0.