get.adobe.com website certification

I just got prompted to update my flash player on my mac running Safari 10.0.1

I followed the link to the update server at get.adobe.com and observed there was no padlock next to the website URL. I then followed the link through from google to the update server to make sure I was going to the right place and not a malicious website and still there was no padlock.

It seems the get.adobe.com website is using a SHA-1 certificate. Surely this is insecure and opens up a potential vulnerability? Especially on mac as users will frequently update their flash software with out a second thought and the process involves entering your administrator password.