Yes, absent tubes
Yes, as Peewee said the mechanism of male infertility in CF patients is bilateral absence of the vas deferens. That's so common an association to the extent that males with infertility due to this defect should be screened for CF (in case it's mild and not diagnosed).
However, please remember that although these patients are infertile but they are not sterile. They make sperms but they are missing the tubes. So taking the sperms and doing Intra Uterine Insemination will solve their infertility.