Long answer… sorry
Historically
The Roman Catholic Church has claimed historically to be the only one true church and that it is only in the true church that people find salvation. The papacy started to gain more power and influence over the other Apostolic Sees somewhere around the 5th century (becoming more powerful around the 7th century with Gregory the Great) the concept of one church under one [earthly] shepherd (the pope) was being ‘exported’ progressively by the Roman See and adopted by people on the western church. With this power, the statements given by the Church were starting to become more authoritative, to the point on which it was said that everyone needed the Roman Catholic Church in order to please God and be saved. For instance, here is a statement from the 14th century that states:
“We declare,say, define, and pronounce that it is absolutely necessary for the salvation of every human creature to be subject to the Roman Pontiff.”
(Pope Boniface VIII, the Papal Bull " Unam Sanctum", 1302 A.D.)
And…
" The most Holy Roman Church firmly believes, professes and preaches that none of those existing outside the Catholic Church, not only pagans, but also Jews and heretics and schismatic’s, can have a share in life eternal; but that they will go into the eternal fire which was prepared for the devil and his angels, unless before death they are joined with Her. and that so important is the unity of this ecclesiastical body that only those remaining within this unity can profit by the sacraments of the Church unto salvation, and they alone can receive an eternal recompense for their fasts, their almsgiving, their other works of Christian piety and the duties of a Christian solder. No one, let his almsgiving be as great as it may, no one, not even if he pour out his blood for the Name of Christ,
can be saved, unless he remain within the bosom and the unity of the Catholic Church."
( Pope Eugene IV, the Papal Bull " Cantate Domino", 1441 A.D.)
However
After the first and second Vatican councils an ‘open door’ was given by the church to people outside the Roman Catholic Faith, who are considered to be in “invincible ignorance” and that are from any other religions and that can be saved outside the church. By invincible ignorance, the church means that it is someone who has not being taught the catholic faith because of different circumstances (not in a Catholic-friendly country, never told what the Roman Catholic Church really believes, etc) and people in this condition are said to be ‘guiltless’ of not believing the faith, here is one statement from Vatican I
“We must hold as of the faith, that out of the Apostolic Roman Church there is no salvation; that she is the only ark of safety, and whosoever is not in her perishes in the deluge; we must also, on the other hand, recognize with certainty that those who are invincible in ignorance of the true religion are not guilty for this in the eyes of the Lord. And who would presume to mark out the limits of this ignorance according to the character and diversity of peoples, countries, minds and the rest?”
Pope of Vatican I, Pius IX (December 9th, 1854)
And here a document after the Second Vatican Council
“Nor does divine Providence deny the help necessary for salvation those who, without blame on their part, have not yet arrived at an explicit knowledge of God, but who strive to live a good life, thanks to His grace. Whatever goodness or truth is found among them is looked upon by the Church as a preparation for the gospel. She regards such qualities as given by Him who enlightens all men so that they may finally have life.”
(Constitution on the Church,
Lumen Gentium, n.16)
SO, to summarize this rather long text… The church has historically held to the view of people outside the Church being not saved. However, within the last 2 centuries, this tendency has changed and some people would argue that is leading towards universalism (hopefully not). That is why we have people these days (as the Sedevacantist) that are pointing out this very issue amongst others.
I hope that this long answer kind of helps. If you are concerned historically, well, read both “sections”, if not, you can read the last (and most current, historically) section.
Sadly, the tradition of the Church seems to be rather “changing” than “unchangeable and firm”