You should only send the application to Northeastern University. If you are chosen to participate, we send all of your application information on to CERN for their files. First the program at Northeastern University is called the REU at CERN Summer Student Program, while the program at CERN is called the CERN Summer Student Programme. While they are essentially the same, CERN hosts our program. Second, we do not require a CV with the application but you may include one if you want.
More information is better than less.
I am a bit confused about the REU program application. I am getting contradicting information form the CERN web page and from the Northeastern web page. Use the CERN application but follow the directions on the Northeastern University web site. DA, Boston, MA 02115. A copy of the transcript is sufficient.