The checkra1n jailbreak tool was updated to version 0.12.3 Thursday afternoon with official support for iOS & iPadOS 14.5 on A7-A11-equipped devices.
Worthy of note, checkra1n users are more likely than any other modern jailbreak user to be taking advantage of Cydia Substrate for tweak injection, so it shouldn’t come as much of a surprise that Cydia Substrate received a similar update on the same day.