You say depend oN the definition of worship
Than use dictionary and tell me If muslim worship Jesus
Well first off, CCC 841 doesn't say that Muslims worship Jesus.
If your response is that Jesus is God, then I say that yes, Jesus is God. However, Jesus is not all of who God is.
Thus it is possible to worship God and not accept Jesus, especially if one is blinded or not really informed about Jesus.
Of course, one won't be worshipping in spirit and in truth, one won't be a true worshipper!
Also, in case this becomes important, the phrase "not accept" does not mean exactly the same thing as "reject".
As for defining worship, there are many different ways
https://www.wordnik.com/words/worship
CCC 841 is probably using something like
"To participate in religious rites of worship."
Or
"The outward recognition of merit; reverence; respect; deference."
If one says that the Muslims are showing that worship to the wrong god, I say that's one way to look at it. The other way is that Muslims are showing that worship to the right God, along with a lot of misinformation (not according to knowledge)!
It is possible to worship something that you do not know
John 4: 22 You worship that which you don't know.