Service Desk loop if username contains comma

All pages/screens on Service Desk, including the Customer Portal, go into an infinite loop if the username of the user that's accessing the Service Desk contains a comma.
It doesn't matter if this user is an Agent, a Collaborator or a Customer, this behaviour happens with them all.

Steps to reproduce:

• Create a new user with a comma on its username (I used fwillig@atlassian,com)
• Log in to the system with this user and access any Service Desk's screen or the Customer Portal