Those who deny the hadith of the prophet saww are called hadith rejectors . They consider normally quran sufficient alone to follow for the religion without recognizing the need to follow the sunna ie sayings or actions of the prophet saww.
What the other Muslims brothers consider these hadith rejectors? A muslim, hypocrite, kafir, or mis-guided etc?
(Whatever is you opinion ,the evidence of it from quran or hadith may be mentioned too for information /discussion, please).