As I'm a bit of an amateur in these matters and since I like to stay in control of my Windows 7 system I install patches manually, through the Microsoft update catalog. I usually rely on ghacks which is easy and usually correct. None of the Windows 7 updates were listed as critical on ghacks, but I recall some updates were referred to as critical on a different website. I took a quick look at the issue, and a quote https://www.thezdi.com/blog/2018/12/11/the-december-2018-security-update-review A number of updates are considered critical, I do not know if that pertains to Windows 7 systems. It mentions one kernel vulnerability that is 'exploited' but not 'critical'. I think it had been referred to on a different website as critical. I installed all updates, but this makes me wonder. Is 'critical' versus 'important' not enough information when deciding if one wants to install updates ?