Ask HN: Security errors on HN?

A few minutes back, while browsing HN through my browser, I got a warning from the browser stating that the site is redirecting to a non HTTPS URL. (Because the site uses HSTS, this was blocked by the browser).

With curl, I got this error message, and I still get it:

curl "https://news.ycombinator.com/news" curl: (51) SSL: no alternative certificate subject name matches target host name 'news.ycombinator.com'

I am not sure what this means, but it sounds worrisome.

Is this some kind of attack (on client or server side), or were there maintenance changes in progress in the last couple of minutes? Did anyone else experience this?