Apple has released tvOS 13.4.8 for its fourth and fifth-generation Apple TV models. It comes over a month after the company seeded tvOS 13.4.5.
No new features have been spotted in the tvOS 13.4.8 software update. It could be that there are under-the-hood fixes and improvements, which is the general case with tvOS updates.
tvOS 13.4.8 is free and can be installed on compatible Apple TVs by going on the Settings app and then to System > Software Update. It will be automatically updated to the newer version if automatic updates are enabled.