What is the ruling on saying that the Prophets—upon them be peace—committed major sins, and is this considered mockery of them that necessitates disbelief?

Scholars are in agreement regarding the infallibility of the Prophets from major sins, and that they do not commit minor sins that would contradict their elevated status. Some sects, such as the Karamiyyah, have deviated by asserting the permissibility of Prophets committing major sins. However, anyone who claims that Prophets commit major sins as a way of diminishing or disparaging their status is, by scholarly consensus, a disbeliever. As for someone who says this due to interpretation or out of ignorance, they are not attributed with disbelief, and their ignorance is excused until the proof is established against them.