Originally Posted by
seattleBH
As others have noted, 1hr is usually fine. You do have to clear immigration but the Sky Priority line (actually it says "Access 1") is usually short and if the airport staff sees it backing up they will take action. Note that unlike other parts of Europe, France does not (yet) accept US passports in the electronic gates.
Be sure to note your actual gate for BOS and follow the signs. 2E-K is just a walk while 2E-L or 2E-M will require a bus ride.
When you get to the gate be proactive and seek out a security contractor who will give you a sticker for your passport.
Are you sure there's an airside bus? 2L and 2M use the little underground train from 2K, although then you clear security in in 2M or whatever when I've done it recently, again with SkyPriority = Acces No. 1 for security and lots of lanes open in 2M (most recently) so it's fast. I think there may be a separate part of the little train to 2L and 2M for people who have already done security elsewhere, with different cars on the train opening on different sides of the track.