: Apple recently fixed a flaw in Notification Services that allowed deleted Signal messages to be recovered. This bug was reportedly used by investigative agencies like the FBI to bypass the encrypted app's intended privacy controls. The fix, released in iOS 26.4.2 on April 22, 2026, improved data redaction to ensure notifications marked for deletion are actually removed.

: When a tool like unc0ver released a jailbreak for the iPhone 11 (A12+ devices) on iOS 13.5, Apple responded within days by releasing a "patch" (iOS 13.5.1) that specifically killed the exploit. Modern State of the iPhone 11

This is the holy grail. A fully custom IPSW where the bootloaders (iBEC, iBSS) have been patched to disable signature checks. You could theoretically restore to this firmware using a tool like sunst0rm or iPwnder32 .

Installing modified iOS firmware on an iPhone 11 is generally not possible because the A13 Bionic chip is not vulnerable to the hardware-level checkm8 exploit. Attempting to bypass these checks risks severe security vulnerabilities, system instability, and the immediate voiding of the Apple warranty. Legitimate alternatives for customization include installing official Apple beta software. For more on secure alternatives, visit the Apple Support website Apple Support Apple security releases