> So introductory-level programming course mistakes are right out.
In my experience it's quite often a really simple mistake that gets you,
even when you're an experienced programmer. I'm quite afraid of simple
off-by-one bug,
places which I didn't fix in copy&paste, basic logic mistakes etc.
IMO
When the user's version is outdated you already display an update notice.
You could add those items from
https://www.mozilla.org/security/known-vulnerabilities/firefoxESR.html
that apply to the current version. Listing particular vulnerabilities makes
it clear that you actually should
update and th
