Overview
- Reporters and a user on X first flagged the change between July 8 and July 9, 2026 when Apple stopped validating installs tied to older baseband builds on select cellular iPhones and iPads.
- The move targets baseband firmware, the low-level software that runs a device’s cellular modem, which is why only cellular models such as iPhone 4/4S/5/5c and several cellular iPad generations are affected.
- With baseband builds unsigned, Finder, iTunes and over‑the‑air installers are rejected and there is no official way to restore or downgrade the listed legacy builds.
- Devices already running their current firmware will keep working, but owners lose the fallback of a fresh reinstall if that firmware later fails and archivists and testers can no longer roll devices back for preservation or compatibility checks.
- This is an uncommon step for Apple because it usually stops signing recent releases after security patches; the change affects a very small group of users since every implicated device and build is more than a decade old.