tldr: If you are running Unraid OS 6 version 6.8.1 or later, the following does not apply (mitigations are in place). If you are running any earlier Unraid OS 6 release, i.e., 6.8.0 and earlier, please read on.
On Jan 5, 2020 we were informed by a representative from sysdream.com of security vulnerabilities they discovered in Unraid OS. Their report is attached to this post. At the time, version 6.8.0 was the stable release.
The most serious issue concerns version 6.8.