A bug that lingered in the Linux kernel for the past five years allowed attackers to bypass some OS security systems and open a root shell. The bug was discovered by Philip Pettersson, a security researcher and CTF (capture-the-flag) player that specializes in Linux vulnerabilities and exploit development. The bugs have been addressed over the last weekend, and this week, downstream Linux distros have slowly pushed patches to their users. In October, researchers discovered Dirty COW, another bug that existed for far longer in Linux kernel code, since 2007.
Source: https://www.bleepingcomputer.com/news/security/five-year-old-bait-and-switch-linux-security-flaw-patched/