The Dogmatic Council of Trent teaches that Judas Iscariot was condemned to Hell

 

Raban.: He “hung himself,” to shew that he was hateful to both heaven and earth.

The Catechism of the Council of Trent, which mentions Judas Iscariot several times, wrote that he possessed "motive unworthy" when he entered the priesthood and was thus sentenced to "eternal perdition."[101] Furthermore, Judas is given as an example of a sinner that will "despair of mercy" because he looked "...on God as an avenger of crime and not, also, as a God of clemency and mercy."[102] All of the council's decrees were confirmed by Pope Pius IV on 28 January 1564.[103] Thus, an ecumenical council, confirmed by the Magisterium of a Pope, affirmed that Judas Iscariot was condemned to Hell. The Council of Trent continued the tradition of the early Church fathers, such as Pope Leo I ("...had [Judas] not thus denied His omnipotence, he would have obtained His mercy..."[104]), and Pope Gregory I ("The godless betrayer, shutting his mind to all these things, turned upon himself, not with a mind to repent, but in a madness of self destruction: ... even in the act of dying sinned unto the increase of his own eternal punishment."[105])

Also, the Decree of Justification, promulgated during Session VI of the Council of Trent, states in Cannon 6, "If anyone shall say that it is not in the power of man to make his ways evil, but that God produces evil as well as the good works, not only by permission, but also properly and of Himself, so that the betrayal of Judas is not less His own proper work than the vocation of Paul; let him be anathema."[106] Here, the Council is making it clear that Judas exercised his own free will to commit the betrayal of Jesus Christ, rather than being predestined by God. Also, by contrasting the actions of Judas to those of Paul, the implication is that Judas is the opposite of a saint (i.e., damned).

Pope St. Leo the Great: "The godless betrayer, shutting his mind to all these things [offerings of God's Mercy], turned upon himself, not with a mind to repent, but in the madness of self-destruction; so that this man who had sold the Author of Life to the executioners of His death, even in the act of dying sinned unto the increase of his own eternal punishment."

“Poor Judas! Above seventeen hundred years have elapsed since he has been in Hell, and his Hell is still only beginning.”

St. Alphonsus Maria de Liguori

Akita Nun Seer's Spiritual Director Reveals a Secret Message

"Like the first Judas, the last pope will sell My Son to the enemy and therefore, the era Of the antichrist pope is coming soon."

Apostate James Martin also denies the traditional Catholic teaching that Judas was condemned

Church Militant: The Saints, Fathers and Doctors of the Church say unanimously that Judas is in Hell. 

Because of the fall of Judas, St. Peter led the Apostles in picking his replacement, who would be St. Matthias. While conducting the election, St. Peter had foreboding things to say about the traitorous Apostle. In Acts 1:16–20, St. Peter declares:

Men, brethren, the Scripture must needs be fulfilled, which the Holy Ghost spoke before by the mouth of David concerning Judas ... he indeed hath possessed a field of the reward of iniquity ... the same field was called ... the field of blood. For it is written in the book of Psalms: Let their habitation become desolate, and let there be none to dwell therein. 

Saint Peter was referring to Psalm 108:6–8: "Set thou the sinner over him: and may the devil stand at his right hand. When he is judged, may he go out condemned; and may his prayer be turned to sin. May his days be few: and his bishopric let another take."

Three famous saints addressed Judas' final disposition:

St. Augustine: "For Judas, when he killed himself, killed a wicked man, and passed from this life chargeable not only with the death of Christ, but also with his own: for though he killed himself on account of his crime, his killing himself was another crime." 

St. Thomas Aquinas: "In the case of Judas, the abuse of grace was the reason for his reprobation, since he was made reprobate because he died without grace."

Pope St. Leo the Great: "The godless betrayer, shutting his mind to all these things [offerings of God's Mercy], turned upon himself, not with a mind to repent, but in the madness of self-destruction; so that this man who had sold the Author of Life to the executioners of His death, even in the act of dying sinned unto the increase of his own eternal punishment."

The damnable end of the traitor Judas

Have you not heard or read in the Psalm, in which the damnable end of the traitor Judas is foretold, how the prophecy spoke of him, ‘Let his prayer be turned into sin?’ (Saint Augustine of Hippo. Sermon 6, no. 2) 

 Catena Aurea St Thomas Aquinas: 

THEOPHYL. But how then did Judas perish? Because he did not continue to the end. Christ speaks of them who persevere. If any sheep is separated from the flock, and wanders from the Shepherd, it incurs danger immediately.  (Catena Aurea) 

 

Augustine: They then who were chosen ate the Lord; he ate the bread of the Lord, to injure the Lord; they ate life, he damnation; for he that eats unworthily, eats damnation to himself (1 Cor 11:27).

 

GREG. By the time of the day is signified the end of the action. Judas went out in the night to accomplish his perfidy, for which he was never to be pardoned.

Leo, Serm., 52, 5: When he says, “I have sinned, in that I have betrayed innocent blood,” he persists in his wicked treachery, seeing that amid the last struggles of death he believed not Jesus to be the Son of God, but merely man of our rank; for had he not thus denied His omnipotence, he would have obtained His mercy.