Well, one was recently fixed. It had to do with a "root user" issue, in which it was possible to get into one's machine without needing a password. It was fixed in the latest release/update of High Sierra, OS 10.13.2. So far that is the only one.
But, quite a few folks are having a number of issues with High Sierra. I myself have not experienced such errors (in fact, hardly any at all), but the slowness of the OS on start up/switching start up devices/switching back to starting up from my internal SSD have me rather dismayed. And there is really nothing earth shattering in High Sierra over Sierra. I keep waffling as to whether I should go back to Sierra or not, and if I did, I would not ge giving up any functionality. IN fact, the speed issues I mentioned would disappear.