This bug is not currently tracked.
Adobe released a new Flash update (version 184.108.40.206) on 2019-02-12. We should soft block (force "Ask to Activate") for all Flash versions strictly < 220.127.116.11 (i.e. <= 18.104.22.168) on all operating systems.
List of old Flash versions:
The Flash block has been updated and staged. Jorge, could you please review and push?
The blocks are now live. I noticed the bug number wasn't updated, so I made that update after approving and re-requested review. Please push the update when you can.
Done, thank you!