No security at MUC but it could get slightly more complicated at FRA, you may want to have a look at the relevant thread as well. That said, my experience (and as much as I try to avoid FRA) is that, depending on where your aircraft docks at (in terms of which gate basically) or, more likely, where you get dropped off (if arriving at a remote stand, which is often the case as I hinted), you may have to go through security again due to the 'funny' airport's layout.

G