UPDATE: The unlocked Galaxy S10 series is now receiving the December 2019 security patch in the US. The software version of this update is G970U1UES2BSKA, G973U1UES2BSKA, and G975U1UES2BSKA for the Galaxy S10e, S10, and S10+ respectively. The size is nearly 200MB.
Samsung’s December 2019 security patch comes with fixes for the 6 critical vulnerabilities in Android OS and 13 Samsung vulnerabilities and exposures in its own OS.
It only brings the security patch, nothing else. The software version of this update is N970U1UES2ASK2 and N975U1UES2ASK2 for the Galaxy Note 10 and Note 10+ respectively. The size of this update is more than 200MB.
If you want to check for the update manually, just go into the device Settings > Software update > Download and install.