Verizon has released a new software update G950USQS2BQL1 for Galaxy S8 and update G955USQS2BQL1 for Samsung Galaxy S8 Plus in the US. The update includes Android December Security patch which fixed Common Vulnerabilities and Exposures discovered in the Android operating system.
In addition, there are device stability improvements, bug fixes and further enhancements for performance.
Software update G950USQS2BQL1 for Galaxy S8 and update G955USQS2BQL1 for Samsung Galaxy S8 Plus will gradually release to everyone. You can also check manually for updates, go to Settings > About device > System update.
Make sure you have enough charge on your device at least 60% to 70% before downloading the update.