OnePlus Adds Android 16 Anti-Rollback: Downgrades And Custom ROMs At Risk

ARB, or Anti-Rollback, technology was reportedly added by OnePlus as part of the ColorOS 16.0.3.501/503 update series. This is a big change for people who like to tinker with software or depend on downgrades. Once a newer build has been installed, the security feature keeps devices from going back to previous firmware versions.

This implementation seems to function at the hardware level in this instance; installing a ColorOS version, like 16.0.3.501, is said to activate an internal security fuse, permanently increasing the device’s rollback protection level. The security system on the motherboard stores this change, so it can’t be undone with normal flashing methods. According to reports, hardware replacement would be necessary to restore the device to its previous rollback state.

The impact of this change can be significant; once Anti-Rollback is activated, users will no longer be able to downgrade to system versions older than the ARB build. Additionally, it may obstruct the installation of older custom ROMs, and the attempt to flash unsupported firmware may result in a hard brick. In particular, this is important because many of the custom ROM builds that are available now were made before these rules were put in place.

An additional repercussion is the diminished utility of “unbrick” utilities and EDL (Emergency Download) tools. Usually, EDL flashing helps get devices back online after failed software changes, but it only works at the software level. If hardware-based rollback protection stops a device from being restored, EDL methods might not be able to do so unless the firmware being flashed meets the new security standards.

Depending on the precise ColorOS build number, some devices, such as the OnePlus 13, OnePlus 15, and OnePlus Ace 5 series, appear to be already impacted. Some OPPO Find X8 models are also thought to be potentially at risk, and the OnePlus 11 and 12 models are currently being analyzed.

Currently, it looks like the ARB restriction only applies to ColorOS. OxygenOS has not yet been confirmed to have the same restriction. It is recommended that users exercise caution when installing updates that end in .500,.501, or.503, particularly if they intend to downgrade firmware, unlock bootloaders, or flash custom ROMs in the future.

Filed in Cellphones. Read more about Android 16 and OnePlus.