Following their last update and the recent ReF00d release, today Sony pushed a PlayStation Vita System Software / Firmware 3.70 update live. 
As always, it's advisable NOT to update as most PlayStation Vita sceners got a PS Vita or PlayStation TV to do fun stuff like jailbreaking, running exploits and homebrew on the handheld console while this revision likely patches the holes preventing such things.
Download: PS Vita Firmware 3.70 Update (US) / PS Vita Firmware 3.70 Update (EU) / PS Vita Firmware 3.70 Update (JP)
We'll update this article as PlayStation Vita scene developers have a chance to examine it since Sony has yet to post an official changelog for the PS Vita 3.70 Firmware update.
Main features in system software update version 3.70
PlayStation Vita system software version 3.70 was released on January 15, 2019. Version 3.70 adds or updates the following features.
New for 3.70

Download: PS Vita Firmware 3.70 Update (US) / PS Vita Firmware 3.70 Update (EU) / PS Vita Firmware 3.70 Update (JP)
We'll update this article as PlayStation Vita scene developers have a chance to examine it since Sony has yet to post an official changelog for the PS Vita 3.70 Firmware update.
Main features in system software update version 3.70
PlayStation Vita system software version 3.70 was released on January 15, 2019. Version 3.70 adds or updates the following features.
New for 3.70
- This system software update improves system performance.