Originally Posted by Stewie Mac

Very straightforward and do-able. If you can get your bp for your IST-CDG flight in advance (either online/app or ask at the checkin in MXP) then no need to even go near the Turkish authorities. There will almost certainly be a TK person on the jetbridge as you disembark saying 'connections' - show him your CDG BP and he will wave you upstairs straight into the departures area, bypassing transit security.