No worries, that is easy job for cobbler to fix. The glue that keeps the outsoles on their place has gave up. It happened if you have worn them during very hot days. Glue and heat doesn't go well together as in most cases glue that is used putting shoes together is hot glue. Hot asphalt and concrete weakens the glue in long run and you end up peeling soles. Or you can glue them back together by yourself if you feel crafty If you deside to take them to cobbler it should be quite cheap and fast fix.