expression, godan verb (-su)
be widely acknowledged; be recognized by everyone
Used when someone's ability, achievement, or quality is so clear that both the person themselves and others accept it without dispute. Often appears in the pattern 自他共に許す～ (a widely acknowledged ...).
See also: 自他共に認める
彼は自他共に許す実力者だ。
He is a person of ability acknowledged by everyone, including himself.
It can be called a masterpiece that everyone, including the creator, recognizes.