Jami` at-Tirmidhi 465
جامع الترمذي#465SahihAbu Sa'eed Al-Khudri narrated that :Allah's Messenger said: "Whoever sleeps past Al-Witr or forgets it, then let him pray it when he remembers it or when he awakens
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih
In-book reference: 3:13