Pope Pius VIII: “Against these experienced sophists the people must be taught that the profession of the Catholic faith is uniquely true, as the apostle proclaims: one Lord, one faith, one baptism. Jerome used to say it this way: he who eats the Lamb outside this house will perish as did those during the flood who were not with Noah in the ark. Indeed, no other name than the name of Jesus is given to men, by which they may be saved. He who believes shall be saved; he who does not believe shall be condemned.” (Traditi humilitati #4, May 24, 1829)

Outside the Catholic Church There is Absolutely No Salvation https://vaticancatholic.com/2nd_edition_final.pdf