Missing authentication in Linksys MR9600, Linksys MX4200

Due to missing authentication, a user with physical access to the device can misuse the mesh functionality for adding a new mesh device to the network  to gain access to sensitive information, including the password for admin access to the web interface and the Wi-Fi passwords.This issue affects MR9600: 1.0.4.205530; MX4200: 1.0.13.210200.