"841 The Church's relationship with the Muslims. "The plan of salvation also includes those who acknowledge the Creator, in the first place amongst whom are the Muslims; these profess to hold the faith of Abraham, and together with us they adore the one, merciful God, mankind's judge on the last day."
This is way above your pay grade your not a canon lawyer. He is talking about within the context of Invincible Ignorance. Notice the word Plan in the statement not salvation. The plan is laid down for salvation.
Christ said He that believe in me has eternal life if he does not he is already condemned. Now does this mean a child who hears or a handicapped mental child or adult who does not understand is condemned. No! What about the rare few who for no fault of their own either what background( Muslim or whatever) never heard or understood what this means. This is noted for these few in the statement. They will be judged on what they do know like the Apostle Paul states and implies. Their conscience is judged.