I'd assume you want something somewhat flexible right? Perhaps flexible plastic adhesive, like from LePage or Loctite. My gf uses stuff like that to repair her boots. I've seen similar products used on cloth and vinyl as well.
If you want something less permanent and if you can hide it well then i'd say an a few really light dabs with an old fashioned hot glue gun? (wouldn't be very strong either but easy to peel off, so long as you don't melt the rubber. There's also various types of fabric glue.
But yea, best bet google "flexible adhesive." There's quite a few options.
