The Ubuntu Kernel team promised at the beginning of the development cycle for Ubuntu 18.04 LTS (Bionic Beaver), Canonical’s seventh long-term supported Ubuntu release to receive security and software update for the next five years, that they target the Linux 4.15 kernel series for the operating system. Linux 4.15 had one of the longest development cycles in the history of kernels for GNU/Linux distributions, due to the numerous patches to mitigate the nasty Meltdown and Spectre security vulnerabilities for 64-bit architectures. It finally arrived at the end of January, so it took a month for Ubuntu Kernel team to implement it.