i'm also with the "don't do it" group. But if you must, walking briskly between 2E and 2F is a much better option than the shuttle bus.

There's also a chance that being a business passenger might save you.
One time when I was flying MXP-CDG-IAD in business on Air France, my 90 minute connection at CDG was down to about 30 minutes when we reached the gate at 2F. I had discussed my connection problem with the flight attendant. When I disembarked, an AF rep holding a sign with my name greeted me at the plane door, directed me downstairs to a van on the tarmac, drove me somewhere else in the airport to clear passport control, then to security near my departure gate in 2E. I boarded literally moments before the door closed.(My checked luggage didn't make it.)

This is nothing to bank on, but still probably worth alerting the flight crew if your JFK-CDG flight is behind schedule.