Apple has released iOS 14.2.1 for the iPhone 12, iPhone 12 mini, iPhone 12 Pro, and iPhone 12 Pro Max only.
iOS 14.2.1 fixes an issue where some MMS messages may not have been received and a bug has been fixed where Made for iPhone hearing devices could have sound quality issues when listening to audio from iPhones
Finally, a problem that causes the Lock Screen to become unresponsive on the iPhone 12 mini has been fixed.
The previous update, iOS 14.2, was a somewhat larger one. It added more than 100 new emoji, incorporated Shazam in the control centre, and introduced new audio and AirPlay features, among other things.
You can update to Apple iOS 14.2.1 by downloading and updating from the Settings app > go to General > Open Software Update.