St. Thomas Aquinas
“Hilary, in commenting on Mat. 26:17, held that Christ did not give His body and blood to Judas. And this would have been quite proper, if the malice of Judas be considered. But since Christ was to serve us as a pattern of justice, it was not in keeping with His teaching authority to sever Judas, a hidden sinner, from Communion with the others without an accuser and evident proof. Lest the Church’s prelates might have an example for doing the like, and lest Judas himself being exasperated might take occasion of sinning. Therefore, it remains to be said that Judas received our Lord’s body and blood with the other disciples, as Dionysius says (Eccl. Hier. iii), and Augustine (Tract. lxii in Joan.).”
Source: St. Thomas Aquinas, Summa Theologica