Security Firm Demonstrates Untethered iOS 27 Jailbreak on iPhone 18 Pro

Security firm Calif demonstrated an untethered jailbreak on an iPhone 18 Pro running iOS 27.0.1 on October 16, 2026. Decrypt reported that the demonstration took place live on stage at Hexacon, an offensive security conference held in Paris. [1]

The exploit marks the first successful untethered and permanent jailbreak on such devices, according to Decrypt. The jailbreak survived a complete device reboot without needing a computer attached to reapply the exploit. [1]

Apple builds the iPhone with strict software restrictions, including signed code requirements, app sandboxing, and a protected startup chain. These controls prevent users from altering how the operating system operates or running unauthorized software. [1]

IOS jailbreaking relies on kernel or userland exploits to bypass the software limits imposed by Apple on its devices. Decrypt reported that Calif has not publicly released any tools or technical details regarding the specific bugs used in the demonstration. [1][5]