OnePlus 6 is getting an update to fix the bootloader flaw
The update is rolling out incrementally, as is the custom for OnePlus, and should reach you within the next few days. For OnePlus 6 owners in India, unfortunately you will not be receiving this update as OnePlus is still in the process of repairing the stability issues in OxygenOS 5.1.6. They stated that OxygenOS 5.1.8 will be available next week to address those issues which will also include the contents of version 5.1.7.
source: mobilesyrup
Things that are NOT allowed: