I don't know of any filed, as at yet, but I do know that a Class Action Law Firm, Keller Rohrback L.L.P., you can check them out via their website: www.krclassaction.com, are investigating the mortgage loan modification practices of several Mortgage Loan Servicers, including Nationstar Mortgage LLC., you mentioned in your question.
The information I saw on their website states that they are interested in hearing from people, like you, who have home mortgage loan with several companies they listed, including Nationstar, or whose house was sold in a foreclosure sale after they tried to have their loan modified , to contact their paralegal Nick Wallace or Attorneys Gretchen Obrist or Lynn Sarko at 800.776.6044 or via email at email@example.com, if they have questions regarding these matters, or if they have information about these Mortgage Loan Companies loan modification practices.
Keller Rohrback have offices in Seattle, and if they evaluate and qualify your situation, who knows, you could be a named Plaintiff in a Class Action against the said Nationstar for this purpose. I have pulled these information to help you with your inquiry, I am not in any way associated with nor do I have or have I ever had any dealings with the said Firm, Keller Rohrback, LLP.
I hope this information helps you. Good luck.
Chief Nnamdi A. Ekenna.