[PSA] Pixel 10 series May 2026 update bootloader anti-rollback

[chenxiaolong]

From: https://developers.google.com/android/images#special_instructions_for_updating_pixel_devices_to_the_may_2026_monthly_release

Warning

The May 2026 update for Pixel 10, 10 Pro, 10 Pro XL and 10 Pro Fold devices contains a bootloader update that increments the anti-roll back version for the bootloader. This prevents the device from rolling back to previous vulnerable versions of the bootloader. After flashing the May 2026 update on these devices you won't be able to flash and boot older Android 16 builds.

This means once you upgrade to the May 2026 update and successfully boot into the OS once, any downgrade will result in a hard brick. Bricks caused by anti-rollback are not recoverable, regardless of what OEM Unlocking is set to.

The easiest way to avoid potential issues is to ensure both slots are on the new bootloader version:

1. Install the May 2026 OTA
2. Reboot into Android and wait for post-install snapuserd merge process to complete
   • If you use Custota, it will tell you. Otherwise, check adb logcat -v color -s update_engine.
   • Or just wait a few minutes
3. Install the May 2026 OTA again