Problem with suspension fork
This is usually due to excessive wear on the bushings in the fork lowers. There is no rebuild kit for that fork that I'm aware of so, your best bet would probably be to replace the fork or if you can get your hands on a second-hand set of lowers for this fork that are in good condition, you could swap them straight over. If there's that much wear on the bushings though, there's probably a build-up of rust on the stanchions abrading them so it'd be better in the long run to just replace the fork as a whole.