https://www.vice.com/en_us/article/d3av8m/apple-emergency-patch-iphone

Apple has just released an emergency patch for the iPhone.

The company was forced to release a patch after it mistakenly made it easier for hackers to jailbreak up to date iPhones with the previous iOS release. In July, Apple released iOS 12.4, an update that reintroduced a bug that had been previously patched. Last week, iPhone hackers and jailbreakers realized Apple’s mistake and published a jailbreak for up to date iPhones—the first time in years it was possible to jailbreak iPhones on the latest version of iOS.