The latest jailbreakable iOS/iPadOS version is 16. x *depending on the chip inside of it*. The semi-tethered checkra1n tool can jailbreak the aforementioned and below, on A9-A10-equipped devices (iPhone 6s & 6s Plus) and iPhone 7 & 7 Plus) running any version of iOS or iPadOS 12-14. x with no strings attached.