Narrated al-Mughirah bin Shu'bah (RA):

Allah's Messenger (ﷺ) said: "The spouse of a lost husband remains his wife till she gets a certain news about his death." [ad-Daraqutni reported it with a Da'if (weak) chain of narrators].

وَعَنْ اَلْمُغِيرَةِ بْنِ شُعْبَةَ ‏- رضى الله عنه ‏- قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ اِمْرَأَةُ اَلْمَفْقُودِ اِمْرَأَتُهُ حَتَّى يَأْتِيَهَا اَلْبَيَانُ.‏ } أَخْرَجَهُ اَلدَّارَقُطْنِيُّ بِإِسْنَادٍ ضَعِيفٍ [1]‏ .‏