HTTPS on website is misconfigured

[mcampbell]

The HTTPS version of the site is evidently misconfigured. My company uses SSL MITM NetSkope as a security product (believe me I rage as much as I can and not get fired over it, but alas), and we can't get to https:// of the site due to the following error:

MismatchCert (Hostname mismatch) Blocked by SSL_HOST_MISMATCH
The destination youmightnotneedjs.com is not reachable.
Contact your IT administrator with the following error:
mode='CLIENT', lname='ips-clear-proxy', rip='<redacted>', rp='443', oip='', op='0', lip='<redacted>, lp='60110', sni='youmightnotneedjs.com', fd='528493', Hostname 'youmightnotneedjs.com' didn't match certificate info, issuer='/C=US/O=DigiCert Inc/CN=DigiCert Global G2 TLS RSA SHA256 2020 CA1', subject='/C=US/ST=California/L=San Francisco/O=GitHub, Inc./CN=*.github.com', notbefore='Jun 9 00:00:00 2024 GMT', notafter='Jun 11 23:59:59 2025 GMT', serial='0DC56EA1ED968F53E5BAC9B62253A8F7', altnames='DNS:*.github.com, DNS:github.com'

One of our infosec experts noted:

it's Github's generic cert that's a Digicert one. I really think it's just people not setting up their config properly. All we can recommend when you run into this is to try accessing it over http rather than https, and maybe dropping the site owner a link to the docs https://docs.github.com/en/pages/configuring-a-custom-domain-for-your-github-pages-site/troubleshooting-custom-domains-and-github-pages#https-errors

I should note that using the http trick does work fine.