Just to add my few cents on this issue.
I have brand new (well not new anymore) DELL Inspiron 5567 machine, I bought back in february. Installed Fedora 25 the first day, and immediately upon Fedora 25 first kernel update, the same issue started appearing, on every single boot.
I also researched alot, and came across number of threads around web, with many people having the same issue. I stumbed upon this thread on Google+
where this guy from DELL, Mario Limonciello, is saying that this is probably some firmware bug, and that these are fake mce errors, not having anything to do with real hardware deffects.
Now, unfortunatelly it's been 6 months since this started happening for me, and it is still there to this day, on Fedora 26. I installed every single BIOS update there was, and there were 4 till now I think, and it is still the same.
Now my machine is on 1.1.5 BIOS version, which is released just 5 days ago for my machine, and like I said, nothing is changed, the same old mce harware errors on every single boot.