grav-plugin-login before 3.8.11 contains a cross-site request forgery (CSRF) vulnerability in the login.regenerate2FASecret frontend task, which regenerates and persists a new TOTP secret for the authenticated session user without any anti-CSRF nonce or Origin/Referer check. Because Grav core dispatches the task from the GET 'task:' URI parameter and the default session cookie is SameSite=Lax, an attacker can lure a logged-in victim to an off-site page that performs a top-level GET navigation, rotating the victim's TOTP secret so their enrolled authenticator no longer matches the server, effectively forcing 2FA re-enrollment. Sites configured with session.samesite: Strict are not affected.