Mahara 15.04 before 15.04.14 and 16.04 before 16.04.8 and 16.10 before 16.10.5 and 17.04 before 17.04.3 are vulnerable to a user submitting potential dangerous payload, e.g. XSS code, to be saved as their name in the usr_registration table. The values are then emailed to the the user and administrator and if accepted become part of the new user's account.