why is my exhaust leaking!!!!!!!

Leaking water? That happens from, condensation, washing, leaving it out in the rain. Nothing to really worry about.It will just blow out the water.
 
I feel that a repack of the muffler is in order, it may be soaked with water and may never dry out.

Do you use steel wool in the muffler, if so that would explain the brown colour, it could be rust.