I am sure this comes up alot but we have a leak in our roof. I have climbed into the attic and can see where it is coming through since it is raining outside. It doesn't appear to be very big. The leak is coming through at the seam of 2 sheets of plywood and one sheet is bowed in a bit. We just bought the house not quite a year ago but the roof appears to be pretty new, maybe within the last 5 years.

My question is if there is a way to fix it without having to replace a big chunk of the roof? Is there a sealant that if I can identify the problem shingles from the outside that can be applied to seal it. Thanks for advise.