I upgraded to 5.8.3 from 5.2 and my /etc/fstab was readable and writable only by root and no one else. The contects appeared unchanged
assigned to msw to take a look at. It did happen on my system too
*** Bug 1869 has been marked as a duplicate of this bug. *** After an upgrade the /tec/fstab file had a mode of 600 This was with the 5.9.2 presnapshot on Fri Mar 26
Fixed in dev-2.7.3-3 -- it was adding devpts without making sure that the permissions remained the same.