The Messenger of Allah ﷺ said, "Cursed is the one who has intercourse with his wife in her anus."
حدثنا هناد عن وكيع عن سفيان عن سهيل بن أبي صالح عن الحارث بن مخلد
قال رسول الله ﷺ ملعون من أتى امرأته في دبرها
This is a citation. [Hasan] Ibn Majah reported it in Nikah, the chapter on the prohibition of approaching women in their rears, hadith no. 1923, from the hadith of Suhayl bin Abu Salih, on this wording, and Busiri graded it sahih. This hadith has very many corroborating narrations among the widely-transmitted hadiths. See Nazm al-Mutanathir min al-Hadith al-Mutawatir, hadith no. 159, and Maani al-Athar by Tahawi, 3/46.