One thing I personally have found confusing is why so many Distros use different kernels and if there was a reason for this and were any security risks. Not being able to find a definitive answer online I asked Jessie Smith at Distrowatch and I received this reply.
The short answer is distributions use (typically) whichever stable
kernel version came out just before the distribution’s latest version
was launched. In Mint’s case, their main edition is based on Ubuntu and
their LMDE is based on Debian. Since they use different bases they use
There are security issues from not using patched kernels, but
distributions which do not constantly update their kernel version (like
Arch does) usually add fixes to their kernel package. So the kernel gets
updated with security fixes even if it is not the latest available
version of the kernel.
This helped me to understand and to cease worrying about it. So if you’ve every wondered now you know.