Is a judgment against a defendant who has not been served with a summons valid?

defense]; Carney v. Simmonds (1957) 49 Cal.2d 84, 95 [an independent action attacking a judgment on the grounds of extrinsic fraud is allowed where it appears that there was a willful failure to give service or that willfully false affidavits of service were filed]; County of San Diego v. Gorham (2010) 186 Cal.App.4th 1215, 1226-1227 [a default judgment entered against a defendant who was not served with a summons in the manner prescribed by statute to establish personal jurisdiction is void].)