Security firm Calif.io demonstrated an untethered jailbreak on an iPhone 18 Pro running iOS 27.0.1 at Hexacon in Paris on October 16. According to NS3.AI, the demonstration showed root access returning after a reboot without a connected computer.

Calif.io has not disclosed the vulnerabilities or released a public tool, but said everything will be released later. Apple had not publicly commented on the demonstration as of Friday. Apple's iOS 27 security notes credit Calif.io and collaborators for two unrelated crash bugs, which the notes do not link to the jailbreak.