Rover owners: Car bleeding from N/S front CV joint [PICS]

Any idea what this leak is? I thought originally the cv boot had perished and leaked but now see it is further up the brake line although does not appear to be brake fluid but some sort of oil.

I have had a few weeks of knocking on speed bumps/potholes and acceleration, as well as steering knocking on lock and quick turns. Suspected replacement steering rack and CV joint required so I wondered if this was related.

Also, is it safe to drive on? What are the like costs for repair?

Many Thanks