If bases are loaded, no outs, and the runner on second gets hit by a batted ball, advancing to third, he is out. But do the runners on first and third get to advance?
Since it's really hard for the runner at second to be in foul territory, this is covered by MLB Rules 5.09(b)(7)
Any runner is out when
(7) He is touched by a fair ball in fair territory before the ball has gone through, or by, an infielder and no other in - fielder has a chance to make a play on the ball. The ball is dead and no runner may score, nor runners advance, except runners forced to advance.
So the runner on third (not forced) must remain at third.
Per 5.05(b)(4), the batter is awarded first base automatically when the runner is struck by the ball. This forces the runner on first to second base.