During installation, the router sent several data packets to an Amazon server in the US. These packets contained the configured SSID name and password in clear text, as well as some identification tokens for this network within a broader database and an access token for a user session that could potentially enable a MITM attack.
Linksys has refused to acknowledge/respond to the issue.
How would they know that the device sends the SSID and password otherwise? If it was encrypted you would not be able to read the content of the packages.
If you get root on the device you can MITM it by extracting session keys