Sunan an-Nasa'i, Volume 6, Book 48, Hadith 5097 (DarusSalam) ⓘ
It was narrated from Hisham bin 'Urwah, from his wife Fatimah, from Asma' bint Abi Bakr, that: The Messenger of Allah [SAW] cursed the woman who affixes hair extensions and the woman who has that done.
أَخْبَرَنِي مُحَمَّدُ بْنُ إِسْمَاعِيلَ بْنِ إِبْرَاهِيمَ، قَالَ حَدَّثَنَا أَبُو النَّضْرِ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنِ امْرَأَتِهِ، فَاطِمَةَ عَنْ أَسْمَاءَ بِنْتِ أَبِي بَكْرٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم لَعَنَ الْوَاصِلَةَ وَالْمُسْتَوْصِلَةَ .
also referenced under: Hadith 5094 (Reference) & Book 48, Hadith 55 (In-Book)