Update: The January security patch has been fully detailed by Google. Check out everything that you need to know about the update. You can also check out BlackBerry's security bulletin on for the update as well, right here.
BlackBerry is beginning to push its monthly security update to the Priv, though at this time it is not exactly known what it addresses. According to a tweet from Michael Clewley, the update is rolling out now, and will hit phones that were bought unlocked from ShopBlackBerry and select carriers first. It is not known which carriers it will push through to, but Clewley does also note that it will be making its way to more carriers next week.
At this time, it is not currently known what the security patches address as far as vulnerabilities, so stay tuned for more information as we receive it. If you own a Priv and are not yet seeing the update, you can check manually by heading into your Settings, About phone and checking for it there.
Source: Michael Clewley (Twitter)