When a player is mounted on another player and the bottom person clicks on the top person with a saddle while looking up it causes both players to go up approx ~10k blocks and fall to their death.

Any updates on this?

Believe it or not, this bug is considered a fun feature for some people. It's probably been in the plugin since the beginning.

Most people disable permission to ride other players. However, I could see this controlled as a config option.

The problem we came across is once you start to reach a certain height the server lags and can crash.