The general rule in the Schengen area is that if you arrive from a Schengen country you can go straight to your next flight without a new security check. (I know that Schengen has nothing to do with security, but I suppose that for logistic reason this was the easiest to organise: if no immigration needed, then no security check needed.)

There are some exceptions to the rule: CDG and LYS are 2 airports where I have been forced to go through security again after arriving from a Schengen country.