Catechism of the Catholic Church, Section 1261
As regards children who have died without baptism, the
Church can only entrust them to the mercy of God, as she
does in her funeral rites for them. Indeed, the great mercy of
God, who desires that all men should be saved, and Jesus'
tenderness toward children, which caused him to say, "Let the
children come to me, do not hinder them" [Mark 10:14,
cf. 1 Tim. 2:4], allow us to hope that there is a way of salvation
for children who have died without baptism. All the more urgent
is the Church's call not to prevent little children coming to
Christ through the gift of holy baptism.