"One indeed is the universal Church of the faithful, outside which no one at all is saved, in which the priest himself is the sacrifice, Jesus Christ, whose body and blood are truly contained in the sacrament of the altar under the species of bread and wine; the bread (changed) into His body by the divine power of transubstantiation, and the wine into the blood, so that to accomplish the mystery of unity we ourselves receive from His (nature) what He Himself received from ours."
--Pope Innocent III and Lateran Council IV (A.D. 1215)
Absolutely. There is no salvation outside the Church. Period. Full stop.
But don't make erroneous assumptions about what "outside the Church" means. Just a few weeks ago was the feast of St. Emerentiana. She died a catechumen: she was never baptized. And of course the good thief was likely not baptized either. Were they members of the Church? Yes. Just not in the typical way.
And we have generally accepted the validity of heretics' Baptism, as long as there is proper form. If you are baptized Protestant you are by that very act incorporated into the Catholic Church....although of course just like any Catholic you can lose your salvation due to heresy, schism, etc.