Making sure I'm doing proper due diligence for an auction

[Konrad R.]

I found a property I'm interested in, and I'm interested in bidding on it through a county auction. My biggest concern would be buying a second position lien on a property. I looked at the final judgment and it states that the following:

1. Plantiff holds a first mortgage lien for the total sum superior to all claims or estates of the Defendants on the following described property

The principal is well over what the house is worth even the ARV. The house was financed during the real estate bubble. I believe it was refinanced because they have owned the property for a long time.

I'm just wanting to do property due diligence. I think the only liens that would be superior would be government liens, so that would include the IRS and property taxes. Is there anything else I need to look into before bidding on the property?