Sunnah.com reference : Book 8, Hadith 56English translation : Book 8, Hadith 1023Arabic reference : Book 8, Hadith 1013
Narrated Abu Hurairah (RA):
Allah's Messenger (ﷺ) said: "He who has intercourse with a woman through her anus is accursed."

[Abu Dawud and an-Nasa'i reported it and the wording is his (an-Nasa'i). Its narrators are reliable, but it was considered to be defective for being Mursal (a missing link after the Tabi'i)].
عَنْ أَبِي هُرَيْرَةَ ‏- رضى الله عنه ‏- قَالَ : قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ مَلْعُونٌ مَنْ أَتَى اِمْرَأَةً فِي دُبُرِهَا }  رَوَاهُ أَبُو دَاوُدَ , وَالنَّسَائِيُّ وَاللَّفْظُ لَهُ , وَرِجَالُهُ ثِقَاتٌ , وَلَكِنْ أُعِلَّ بِالْإِرْسَالِ  1‏ .‏‏1 ‏- صحيح بشواهده .‏ وفي "الأصل" تفصيل ذلك.‏