[coreboot] Does the 62xx Series Opteron work *securely* without microcode?

I know the 63xx has a very fatal NMI exploit, but according to the 
libreboot (oh no) website the 62xx works safely out of the box without 
microcode however I would like to confirm if this is actually true.

I looked at the errata .pdf from the AMD website but I didn't see 
anything that seemed significant.