iOS 27.0.1 Untethered Jailbreak Demonstrated on iPhone 18 Pro

Key Takeaways

• Cybersecurity firm Calif has publicly demonstrated an untethered jailbreak for iOS 27.0.1 on the new iPhone 18 Pro.
• The demonstration, occurring at Hexacon 2026, confirmed full root access and persistence across reboots.
• This “untethered” capability represents a significant achievement, bypassing Apple’s robust hardware and software security measures.
• While the specific vulnerabilities exploited remain undisclosed, such exploits are highly sought after by sophisticated threat actors.
• Users should remain vigilant and install Apple’s security updates promptly to mitigate potential risks.

Untethered iOS 27.0.1 Jailbreak Achieved on iPhone 18 Pro

Security researchers from the cybersecurity firm Calif have successfully demonstrated an untethered jailbreak on Apple’s recently released iPhone 18 Pro, running the latest iOS 27.0.1 operating system. This marks one of the earliest public indications that Apple’s newest mobile hardware and software can be fully compromised.

Live Demonstration at Hexacon 2026

The breakthrough was showcased live at Hexacon 2026, a prominent offensive security conference organized by Synacktiv in Paris on October 16, 2026. The demonstration comes merely weeks after the iPhone 18 Pro and iOS 27.0.1 became available to the public, underscoring the rapid pace at which sophisticated exploits can be developed.

During the presentation, the Calif team rebooted the iPhone 18 Pro. The device powered on, displayed the Apple logo, reached the lock screen, and was subsequently unlocked using its passcode. Crucially, the jailbreak persisted and re-engaged autonomously without any physical connection to a computer, illustrating its “untethered” nature. This characteristic signifies that the exploit survives a complete device reboot, representing the most challenging and uncommon form of jailbreak to achieve on contemporary iPhones.

Technical Details of the Compromise

Following the reboot, the researchers established an SSH connection to the device via port 2222 and logged in with root privileges. The execution of the id command confirmed full root access with uid=0. Further system information was gathered, with the uname output revealing Darwin Kernel 27.0.0, built on XNU 13432.2.10 for the T8160 chip, identifying the model as iPhone19,2. The sw_vers command validated iOS 27.0.1, build 24A446, and neofetch indicated 67 packages installed via dpkg, with a reported uptime of just two minutes.

Achieving root access on a modern iPhone typically necessitates chaining multiple vulnerabilities. This process often involves escaping the application sandbox, escalating privileges to control the kernel, and circumventing hardware-backed security mechanisms such as Pointer Authentication Codes (PAC). Maintaining this level of access after a system reboot presents an even greater challenge, as Apple implements stringent code integrity checks during the startup sequence.

The specific vulnerabilities exploited by the Calif researchers have not been disclosed, and no public jailbreak tool has been released. Apple previously addressed over 120 flaws in the iOS 27 release on September 14, including 20 kernel vulnerabilities, as detailed in its official security notes. This update was part of a broader security release that patched 273 vulnerabilities across various Apple devices. Earlier in the year, Apple also patched an actively exploited iOS zero-day vulnerability that had been used against targeted individuals.

What You Should Do

While the method demonstrated by Calif is not publicly available, the existence of such an exploit underscores the ongoing threat landscape for iOS devices. Sophisticated actors, including state-sponsored groups and commercial spyware vendors, often leverage similar vulnerability chains.

• Install Updates Promptly: Always install Apple’s security updates as soon as they become available. These updates often contain critical patches for vulnerabilities that could be exploited.
• Maintain Device Hygiene: Regularly review installed applications and remove any that are unfamiliar or unused.
• Exercise Caution with Links and Attachments: Be wary of suspicious links or attachments in emails and messages, as these are common vectors for initial compromise.
• Enable Strong Passcodes: Ensure your device has a strong, unique passcode and biometric authentication enabled.

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