At the moment, Ubuntu 15.10 is in development and the Final Beta build will be ready for download and testing on September 24, 2015. Therefore, we can only assume that the final release of the Ubuntu 15.10 (Wily Werewolf) operating system, due for release on October 22, 2015, will be based on the Linux 4.2 kernel series. At the moment, the OS is based on a kernel from the Linux 4.1 LTS series.