A flaw was found in the kernel that can allow local (not remote) users to get root access. It's not a big concern for solo desktop users like us since we probably already have the ability to gain root :)
If you're sharing a Linux system with an expert or administer Linux machines for others then you know what to do. Major distros have already rolled out patches and I expect most will have soon. It affects kernel versions up to and including 4.9.11.
http://www.pcworld.com/article/3173612/security/eleven-year-old-root-flaw-found-and-patched-in-the-linux-kernel.html
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-6074