12 USC 3765 - Effect of sale

A sale, made and conducted as prescribed in this chapter to a bona fide purchaser, shall bar all claims upon, or with respect to, the property sold, for each of the following persons:
(1) Notice recipients 
Any person to whom the notice of default and foreclosure sale was mailed as provided in this chapter, and the heir, devisee, executor, administrator, successor, or assignee claiming under any such person.
(2) Subordinate claimants with knowledge 
Any person claiming any interest in the property subordinate to that of the mortgage, if such person had actual knowledge of the foreclosure sale.
(3) Nonrecorded claimants 
Any person claiming any interest in the property, whose assignment, mortgage, or other conveyance was not duly recorded or filed in the proper place for recording or filing, or whose judgment or decree was not duly docketed or filed in the proper place for docketing or filing, before the date on which the notice of the foreclosure sale was first served by publication, as required by section 3758 (3) of this title, and the executor, administrator, or assignee of such a person.
(4) Other persons 
Any person claiming an interest in the property under a statutory lien or encumbrance created subsequent to the recording or filing of the mortgage being foreclosed, and attaching to the title or interest of any person designated in any of the foregoing paragraphs.