Sunan Ibn Majah
1964
Sahih+2

Maimunah bint Harith narrated:that the Messenger of Allah married her when he was Halal (not in Ihram). (Sahih).He (one of the narrators-Yazid) said: "And she was my maternal aunt and the maternal aunt of Idn 'Abbas also

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi