The Path of Exile Twitter has been updated with a notification to players that the game servers are currently undergoing a DDoS attack. The notification was made early yesterday afternoon and while the tweet says that the issue would be resolved "soon", no update from the dev team has been posted.
Our site has been suffering from DDOS attacks for several hours now. We expect to have it back up soon.— Path of Exile (@pathofexile) November 20, 2018
We'll keep you posted!
Thanks, anonymous tipster!