Lots of things in catholicism are necessary for salvation. Which is just one of the reasons its a false religion. Unless of course you are invincibly ignorant; ccc 1260, then you don't need any of it. Another false gospel. Btw, how many other religions can say they have more than one false gospel? Rome has at least two. One for the tried and true faithful, and one for those that have no clue about Jesus or the church. I'm sure the devil is quite impressed with his handiwork.
Lets count them and find out.
1) ccc1129 -The Church affirms that for believers the sacraments of the New Covenant are necessary for salvation.(i.e.-works based salvation)
2) out side the church, there is no salvation.
ccc846 How are we to understand this affirmation, often repeated by the Church Fathers? Re-formulated positively, it means that all salvation comes from Christ the Head through the Church which is his Body:
Basing itself on Scripture and Tradition, the Council teaches that the Church, a pilgrim now on earth, is necessary for salvation:
the one Christ is the mediator and the way of salvation; he is present to us in his body which is the Church. He himself explicitly asserted the necessity of faith and Baptism, and thereby affirmed at the same time the necessity of the Church which men enter through Baptism as through a door. Hence they could not be saved who, knowing that the Catholic Church was founded as necessary by God through Christ, would refuse either to enter it or to remain in it.
3) Mary is necessary for salvation--Liguori's "Glories of Mary" Ch5
Only those who have no faith will deny that it is very useful and commendable to have recourse to the intercession of Mary. But what we intend to prove here is that Mary’s intercession is not only useful but necessary for salvation: not absolutely, but morally, necessary
. This necessity goes back to the very will of God Himself, Who had decreed that all the graces He gives human beings should pass through Mary’s hands (emphasis added by SCF). This is the opinion of St. Bernard — an opinion which we may now safely call the general opinion of Theologians and Doctors.
I let other people add to this list.