Do EU sanctions on Russia extend to Russian nationals applying for EU funded positions in Europe? For example, can a Russian national apply for a fellowship within an existing MSCA COFUND?

Yes, this is possible. The European Commission has decided not to engage into further cooperation projects with Russian and/or Belarussian entities, but this does not concern individual researchers from these countries. As long as they are not targeted by any sanctions, they can be recruited in projects. Russian nationals could also apply and receive MSCA PF. However, a challenge may be the various countries’ immigration regulations, which have to be carefully considered.