I heard the Prophet ﷺ saying, "Whoever claims to be the son of a person other than his father, and he knows that person is not his father, then Paradise will be forbidden for him." I mentioned that to Abu Bakra, and he said, "My ears heard that and my heart memorized it from Messenger of Allah ﷺ.  

سَمِعْتُ النَّبِيَّ ﷺ يَقُولُ مَنِ ادَّعَى إِلَى غَيْرِ أَبِيهِ وَهْوَ يَعْلَمُ أَنَّهُ غَيْرُ أَبِيهِ فَالْجَنَّةُ عَلَيْهِ حَرَامٌ فَذَكَرْتُهُ لأَبِي بَكْرَةَ فَقَالَ وَأَنَا سَمِعَتْهُ أُذُنَاىَ وَوَعَاهُ قَلْبِي مِنْ رَسُولِ اللَّهِ ﷺ  

The Prophet ﷺ said, "Do not deny your fathers (i.e. claim to be the sons of persons other than your fathers), and whoever denies his father, is charged with disbelief."  

عَنِ النَّبِيِّ ﷺ قَالَ لاَ تَرْغَبُوا عَنْ آبَائِكُمْ فَمَنْ رَغِبَ عَنْ أَبِيهِ فَهُوَ كُفْرٌ