Specifically concerning non-Catholic Christians, the Catechism notes:
The Church knows that she is joined in many ways to the baptized who
are honored by the name of Christian, but do not profess the Catholic
faith in its entirety or have not preserved unity or communion under
the successor of Peter. Those who believe in Christ and have been
properly baptized are put in a certain, although imperfect, communion
with the Catholic Church. With the Orthodox churches, this communion
is so profound that it lacks little to attain the fullness that would
permit a common celebration of the Lord’s Eucharist. (CCC 838)
The way I read this, the answer is "yes, but they' don't have the full Truth. If they've been properly baptized and believe in Christ, they are associated with the Church, but imperfectly."
This agrees with http://www.catholic.com/quickquestions/what-is-the-relationship-between-the-church-and-baptized-protestants
What relationship does the Catholic Church perceive to exist between
itself and various Protestants (the baptized ones who still accept
Validly baptized Protestants are regarded as true Christian brothers
and sisters who are in imperfect relationship with the Church. The
nature of the imperfections is as varied as Protestantism itself. The
idea at work here is that the faith is an incarnational thing, not
just a "spiritual" (disembodied) thing—just like Jesus himself. Thus,
it is possible to be out of union with the Church "bodily"
(structurally, sacramentally, liturgically), yet still have a
spiritual unity with the Church. Likewise, it is possible to be
"bodily" united to the Church yet cease to be in communion with her
spiritually (as an apostate Catholic is if he keeps going to Communion
yet rejects the creed or continues unrepentant in grave sin). The
latter form of disunity with Church is more serious than the former.
Also, from http://www.ewtn.com/library/ANSWERS/dontbelieve.HTM (Item # 7)
Catholics do not believe that Protestants who are baptized, who lead a good life, love God and their neighbor, and are blamelessly
ignorant of the just claims of the Catholic Religion to be the one
true Religion (which is called being in good faith), are excluded from
Heaven, provided they believe that there is one God in three Divine
Persons; *that God will duly reward the good and punish the wicked;
that Jesus Christ is the Son of God made man, who redeemed us, and in
whom we must trust for our salvation; and provided they thoroughly
repent of having ever, by their sins, offended God.
Catholics hold that Protestants who have these dispositions, and who
have no suspicion of their religion being false, and no means to
discover, or fail in their honest endeavors to discover, the true
Religion, and who are so disposed in their heart that they would at
any cost embrace the Roman Catholic Religion if they knew it to be the
true one, are Catholics in spirit and in some sense within the
Catholic Church, without themselves knowing it. She holds that these
Christians belong to, and are united to the "soul," as it is called,
of the Catholic Church, although they are not united to the visible
body of the Church by external communion with her, and by the outward
profession of her faith.
Very different is the case of a person who, having the opportunity,
neglects to learn from genuine trustworthy sources what the Catholic
Religion is and really teaches, fearing, that were he to become
convinced of the truth of the Catholic Faith, he would be compelled by
his conscience to forsake his own religion, and bear the worldly
inconveniences attached to this step. This very fear shows a want of
good faith, and that he is not in that insurmountable ignorance which
could excuse him in the sight of God, nut that he is one of those of
whom it is said in Psalm xxxv. 4, "He would not understand that he
might do well."
Fairness, no less than common sense, teaches that a man should study
and examine the teaching of the Catholic Church from Catholic sources
before condemning her. Surely no man ought to reject Catholic doctrine
if he has not made himself well acquainted with them. Nor is is fair
to form a judgment from misrepresentations made by ill-informed,
interested, or prejudiced persons; one should rather, by the study of
authorized Catholic works, judge of the truth with that calm and
unprejudiced mind which the all-important subject of Religion
deserves. Thus having heard both sides, you will be in a state to pass
a right judgment and not in danger of being misled by prejudice.
Our Saviour gave no hope of salvation to the Samaritan woman unless
she entered the one true Church of the tine, saying to her who was
destitute of a sure guide: "You adore that which you know not; we
adore that which we know; for SALVATION IS OF THE JEWS". (St John iv.
22.) So likewise there is no salvation for any one who, having by God's grace come to the knowledge of the truth, obstinately refuses to
join the true Church of God.
That third paragraph on, particularly the very last sentence, indicates to me that the hope of salvation for protestants doesn't extend to those that flat-out refuse to learn about what the Catholic Church really teaches.