Muslim reported from Maimunah (RA) herself:

"The Prophet (ﷺ) married her when he was not in the state of Ihram."

وَلِمُسْلِمٍ : عَنْ مَيْمُونَةَ نَفْسِهَا { أَنَّ اَلنَّبِيَّ ‏- صلى الله عليه وسلم ‏-تَزَوَّجَهَا وَهُوَ حَلَالٌ } [1]‏ .‏