Unknown · Openproject · CVE-2026-33667
**Name of the Vulnerable Software and Affected Versions**
OpenProject versions prior to 17.3.0
**Description**
Two-factor authentication (2FA) OTP verification in the 'confirm otp' action of the `two factor authentication` module lacks rate limiting, lockout mechanisms, or failed-attempt tracking. The `brute force block after failed logins` setting only tracks password login failures and does not apply to the 2FA stage. Additionally, the `fail login` and `stage failure` functions do not increment counters, lock accounts, or introduce delays. Because the default Time-based One-Time Password (TOTP) drift window of ±60 seconds allows multiple valid codes simultaneously, an attacker with a user's password can brute-force the 6-digit TOTP code. This same issue affects backup code verification, potentially allowing a complete 2FA bypass.
**Recommendations**
Update to version 17.3.0.