Can buyers bankruptcy affect owner finance property?

I'm not exactly sure what you mean by "come after".   If you wish to foreclose, you must apply to the bankruptcy court for permission to do so.  If you have the first mortgage on the property, then you must be paid if the property is sold, regardless of whether it is sold by the bankruptcy trustee or the debtor. You don't disclose which chapter of bankruptcy was filed, so I have no way to advise whether they are seeking to bring current the payments on the mortgage (such as through a Chapter 13 case). You should consult with a bankruptcy attorney in the location where the case was filed for more details. Mark Markus has been practicing exclusively bankruptcy law in California since 1991.  He is a Certified Specialist in Bankruptcy Law by the State Bar of California Board of Legal Specialization,  AV-Rated by martindale.com, and A+ rated by the Better Business Bureau.