All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Denying and rejecting the confirmed Ahadeeth due to misinterpretation or due to believing that they are not confirmed from the Prophet is not Kufr (disbelief), and this is what is apparent from the state of those who say: “If the Prophet Muhammad had said it in front of him, I would have accepted it.”
Rather, the one who becomes a disbeliever is the one who rejects the Ahadeeth while acknowledging that they are confirmed on the authority of the Prophet .
Imam Is-haq ibn Rahawayh said: “Whoever a narration of the Prophet has reached him while he acknowledges its authenticity, then rejects it without misinterpretation, then he is a disbeliever. This was quoted by Ibn Hazm in the book entitled al-Ihkaam fi Usool al-Ahkaam.
This is all in regard to the confirmed Ahadeeth, as for the Ahadeeth that are not confirmed – such as the weak or fabricated ones – then there is no problem that rejecting them is not Kufr.
Allah Knows best.