While not a foreclosure, I purchased a "short sale" home several years ago. It's probably the same with foreclosure, but once you get past any realtor that may be involved and negotiate the actual price of purchase with the bank(S) involved, all you owe is that purchase price agreed between you and the bank(S). It's a brand new loan generated (unless you pay with cash), and has nothing to do with the previous owners money owed. The previous owner would then still be liable for whatever they owed on the house, which is no longer in their possession, or whatever they can negotiate down with the bank(S) them selves.