Well, you do have to fix it manually (actually I don’t really see another way), but luckily it is not a lot of work. Simply edit the release, go to the track list and remove disc 10. Then leave an edit note to explain what you did and enter the edit.
That’s assuming that CD 10 is wrong. As I understand the OP’s description, however, it’s CD 4 that is wrong and should be removed (and replaced with the correct one, I guess).