Do as Greg says [1][2]:

> All users of the 4.8 kernel series must upgrade.

Changes for Linux 4.8.13 [3][4]:

> A few moments ago, renowned Linux kernel maintainer Greg Kroah-Hartman
> had the pleasure of announcing the general availability of the Linux
> kernel 4.8.13 and Linux kernel 4.4.37 LTS maintenance updates.
>
> While many rolling GNU/Linux distributions have just received the
> Linux 4.8.12 kernel, it looks like Linux kernel 4.8.13 is now
> available with more improvements and bug fixes, but it's not a major
> milestone.  According to the appended shortlog and the diff since last
> week's Linux 4.8.12 kernel release, a total of 46 files were changed,
> with 214 insertions and 95 deletions.
>
> "I'm announcing the release of the 4.8.13 kernel. All users of the 4.8
> kernel series must upgrade," said Greg Kroah-Hartman. "The updated
> 4.8.y git tree can be found at:
> git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
> linux-4.8.y and can be browsed at the normal kernel.org git web
> browser:
> http://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary."
>
> ### Minor AMDGPU improvements, lots of ARM64 fixes ###
>
> Looking at the changes, we can notice that Linux kernel 4.8.13 brings
> updated ADMGPU and Radeon graphics drivers with fixes for the
> availability of port PM, lots of ARM64 (AArch64) improvements, but
> also some small fixes for the x86 and ARC architectures, updated ATA
> (libata-scsi), CLK (sunxi), Intel i915, MediaTek, wireless (Marvell
> mwifiex), PCI-E, PWM, and SCSI drivers.
>
> There's also a fix for the OverlayFS file system, support for
> detecting missing primaryif during tp_send as an error to the
> B.A.T.M.A.N.  Advanced routing protocol, a few KVM (Kernel-based
> Virtual Machine) improvements, and a bunch of core kernel and mm
> changes. The Linux kernel 4.8.13 source archive is now available for
> download from kernel.org and we recommend to update as soon as
> possible.

Changes for Linux 4.8.14 [5][6]:

> A few moments ago, Linux kernel maintainer Greg Kroah-Hartman announced
> the release of Linux kernel 4.8.14, the fourteenth maintenance update to
> the most advanced kernel series.
>
> Believe it or not, Linux kernel 4.8.14 is here only two days after the
> December 8 release of Linux kernel 4.8.13, which wasn't a big patch.
> However, it looks like today's update brings some more improvements, and
> according to the appended shortlog and the diff since the previous
> version, it changes a total of 56 files, with 388 insertions and 164
> deletions.
>
> "Turns out I'm going to be on a very long flight early tomorrow morning,
> so I figured it would be good to get this kernel out now, instead of
> delaying it by an extra day. So, I'm announcing the release of the
> 4.8.14 kernel," said Greg Kroah-Hartman in today's mailing list
> announcement. "All users of the 4.8 kernel series must upgrade."
>
> ### Mostly networking improvements and updated Ethernet drivers ###
>
> Linux kernel 4.8.14 is all about networking improvements, as it updates
> the networking stack with a bunch of changes and fixes to the Datagram
> Congestion Control Protocol (DCCP), Distributed Switch Architecture
> (DSA), IPv4, IPv6, Layer 2 Tunneling Protocol (L2TP), Netlink, packet
> scheduler, and Transparent Inter-process Communication (TIPC)
> implementations.
>
> Additionally, there are various enhancements to the Broadcom, Cadence,
> Marvell, and Renesas Ethernet network controller drivers, as well as to
> the Broadcom support for the Distributed Switch Architecture (DSA)
> subsystem. Last but not least, Linux kernel 4.8.14 fixes a couple of
> issues with the SPARC hardware architecture. As usual, you are urged to
> update your kernel packages as soon as possible.
>
> Linux kernel 4.8.14 is now available for download from kernel.org or via
> our web portal. Also today, Greg Kroah-Hartman released the
> thirty-eighth maintenance update to the long-term supported Linux 4.4
> kernel series, so if you're using a GNU/Linux distribution powered by
> that kernel, you are urged to update as soon as possible to Linux kernel
> 4.4.38 LTS.

This release also fixes the local privilege escalation CVE-2016-8655
[7][8].

[1] https://lkml.org/lkml/2016/12/8/552
[2] https://lkml.org/lkml/2016/12/10/127
[3] http://news.softpedia.com/news/linux-kernel-4-8-13-launches-with-arm64-and-amdgpu-improvements-kvm-fixes-510831.shtml
[4] https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.8.13
[5] http://news.softpedia.com/news/linux-kernel-4-8-14-hits-the-streets-with-numerous-networking-improvements-more-510874.shtml
[6] https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.8.14
[7] https://www.heise.de/newsticker/meldung/Root-Rechte-durch-Linux-Luecke-3565365.html
[8] http://seclists.org/oss-sec/2016/q4/621