OnePlus Adds Hardware Anti-Rollback in ColorOS 16.0.3.501/.503 That Can Hard Brick the 13, 13T and 15

Overview

• Community reports indicate devices that flash older ColorOS, OxygenOS or pre-update custom ROMs can enter an unrecoverable hard-brick state, with some cases reportedly requiring a motherboard replacement.
• Previously used unbrick methods, including unauthorized 9008 tools and Chimera firehose programmers, reportedly fail after the anti-rollback change.
• The behavior has been observed on Chinese ColorOS builds for the OnePlus 13, 13T and 15, while older models like the OnePlus 12 have not been reported with the mechanism.
• Removal of official OxygenOS rollback packages for the OnePlus 13 has raised concern that the anti-rollback system could extend to global units sharing the codebase.
• OnePlus has not provided an official explanation, with reporting noting industry precedent for anti-rollback measures framed as security protections.