Apple has released iOS 13.5.1 and iPad OS 13.5.1 which fixes the vulnerability used in the unc0ver jailbreak.
The unc0ver jailbreak was released in May and supports iPhones that run iOS 11 up to iOS 13.5. It takes advantage of a zero-day vulnerability, meaning it is a flaw in the iOS system that is unknown to or unaddressed by Apple.
The jailbreak is used to add extra features to Apple devices such as customization options. However, Apple doesn’t recommend jailbreaking and have released a fix.
Aside from iOS 13.5.1 and iPadOS 13.5.1, Apple has also released watchOS 6.2.6.