Haskell can resume playing on September 30, a day before Wasps meet Bath at Adams Park.
It is another blow for the Premiership champions, whose season has started with succcessive defeats against London Irish, Worcester and Northampton.
Haskell was cited following an incident during Wasps' 11-10 loss to Worcester on September 14. He has the right of appeal.
His team-mate though, lock Richard Birkett, has avoided suspension after being cited for stamping in the same game.
Birkett was reprimanded and warned by a Rugby Football Union disciplinary panel chaired by His Honour Judge Jeff Blackett.