https://support.microsoft.com/en-us/topic/kb3135749-fix-incorrect-group-members-are-obtained-when-you-run-the-xp-logininfo-stored-procedure-in-sql-server-2012-or-sql-server-2014-a69c794e-96d5-e729-3d7a-e2a56dbea745
KB3135749 - FIX: Incorrect group members are obtained when you run the xp_logininfo stored...
Fixes an issue in which incorrect group members are obtained when you run the xp_logininfo stored procedure in SQL Server.