Samsung has recently released the December 2023 security update to the Galaxy Note 20 series for global users. Now, according to the latest information, the all-new security update is available for the factory-unlocked versions of the devices in the US.
Galaxy Note 20 getting December 2023 security update
As per the update changelog, the latest update is rolling out with the firmware version N98xU1UES6HWK1 which fixes over 75 security flaws.
You can download the latest update via Settings > Software update > Download and install.