ZTNET is a ZeroTier web UI for private controllers with multiuser and organization support. Prior to 0.8.0, any authenticated low-privilege user can permanently deactivate another account, including an administrator, through `POST /api/auth/user/invalidateUser`. In `src/pages/api/auth/user/invalidateUser.ts`, `getServerSession` checks only that a session exists and does not compare `session.user.id` with the client-supplied `userId`. Supplying a victim's `userId` and a `deviceId` for which no matching pair exists in `UserDevice` makes the handler set the target account's `isActive` to false. Login is then refused by `src/server/auth.ts` with `account-expired`. An attacker needs only a normal