When is the claim of infallibility for a person considered major disbelief (kufr akbar)?

The Ummah has agreed upon the infallibility of the Messengers in bearing and conveying the Message, and that they are protected from falling into major sins. As for minor sins, most scholars believe that they are not immune from them, and if they occur, they are not condoned.

There is no sin upon whoever believes in their infallibility from minor sins, as the issue is a matter of dispute among scholars.

As for those other than the Prophets, believing in their infallibility is blameworthy extremism, for no one is infallible except the Prophets and Messengers, peace be upon them.

Muslims have agreed that everyone other than the Messenger, his words can be taken or left.

Whoever claims infallibility for anyone in everything they say after the Messenger, peace and blessings be upon him, is misguided, and there is dispute and detail regarding their excommunication.