Is it permissible to act upon weak hadiths?

Question:
Abu Ibrahim says: Shaykh Salih, regarding the weak hadiths that are cited in the virtues of actions, do we act upon them?

Answer:
Weak hadiths are not all of the same degree. Some are weak but have corroborating narrations that strengthen them, and a weak hadith may be raised to the level of hasan (good) for other reasons. As for weak hadiths that are severely weak, these are not acted upon. However, hadiths that have not reached the extreme of weakness, or that have corroborating narrations, it is permissible to act upon them in matters of encouragement, warning, and exhortation. But as for establishing a legal ruling from them, whether it be something lawful, forbidden, a punishment, a hudud penalty, or otherwise, this is not permissible, and no legal ruling is established by them. If it is known that a hadith is fabricated, it is not permissible to act upon it. Yes.