Last week, Apple released the iOS 26.5.2 update for iPhones, patching close to 29 WebKit security vulnerabilities, ensuring the iOS experience remains safe and uninterrupted. Now, following that, the Cupertino brand has officially barred downgrades to iOS 26.5.1 and iOS 26.5 by unsigning them.
Apple Stops Signing iOS 26.5.1 and iOS 26.5 to Discourage Downgrades
Spotted by 9to5Mac, Apple has now stopped signing the iOS 26.5.1 and iOS 26.5 updates indefinitely. When Apple "unsigns" an iOS version, it means that the company's servers will no longer provide the digital handshake required to install that specific software. It completely blocks access to it.
So, for iPhone users who have already installed the latest iOS 26.5.2 update, it is now practically impossible for them to install older iOS versions. There is no going back to iOS 26.5.1 or iOS 26.5 on these iPhones, even if the current iOS update takes a hit on performance and battery.
While this is indeed frustrating for those who prefer having a "rollback" safety net, it is a necessary move that ensures the safety and security of iPhone users. Apple has historically maintained its stance of killing older versions of iOS to prevent threat actors from exploiting known flaws and vulnerabilities.
Back in May 2026, Apple also unsigned iOS 26.5, followed by iOS 12.5.7, iOS 15.8.5, iOS 16.2, iOS 16.7.12, iOS 18.7.3 and more. Such safeguards are necessary as the Cupertino brand has faced a lot of challenges recently.
From the infamous DarkSword attack in iOS 18 to a kernel-level exploit in iOS 15, it has become crucial for the brand to maintain its system integrity and the surest way to do so is by blocking access to older iOS versions.
