The Gospel of Judas was a writing associated with the Gnostic sect of the Cainites, who regarded Judas as a hero. It was known in the second century but is not part of the New Testament writings.
The work is not used as a canonical Gospel and is mentioned only in reports about the Cainites and their beliefs.
Irenaeus, Epiphanius, and Theodoret refer to it, but no quotation from the writing is preserved in the supplied material.