User can send a chat that contains an XSS opportunity that will then run when the chat is sent and on subsequent page loads. Given the minimum requirement for a user to send a chat is to be given access to a workspace via an admin the risk is low. Additionally, the location in which the XSS renders is only limited to the user who submits the XSS. Ultimately, this attack is limited to the user attacking themselves. There is no anonymous chat submission unless the user does not take the minimum steps required to protect their instance.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.