You can probably find one close to that weight but it might be difficult. My full-suspension XC bike is 26.5 lbs stock and has quite a bit of CF on it. It all depends on how beefy you want the bike to be and how much you want to pay. A Litespeed Sewanee tricked out with a bunch of CF and lightweight XTR parts will probably squeak in under 25 lbs. but it won't be cheap. You're looking at a $6,000 pricetag there. If you drop back to some more reasonably priced aluminum parts for handlebar and seatposts and go with an LX drivetrain, you can get it to just 25 lbs. for around $3,500. The frame weight of the Sewanee is 4.4 lbs. so given that parts mix, that's about the frame weight you want to be shooting for.