952
Let's Encrypt is 10 years old today !
(letsencrypt.org)
Happy birthday to Let's Encrypt !
Huge thanks to everyone involved in making HTTPS available to everyone for free !
Wildcard certs are perfectly fine. Your own instance lemm.ee is using one right now.
Obviously there could be issues if subdomains are shared with other sites, but if the whole domain is owned by 1 person, what does it matter?
If one system is somehow compromised, the attacker could effectively impersonate all the systems on your entire domain if they had the wildcard cert. Maybe it's not a huge deal for individuals but for companies or other organisations it could be extremely dangerous.
If someone wanted a wildcard cert at work I would be very cautious before I even considered issuing one. Unfortunately there are a few wildcard certs on our domain, but those are from before my time.
Having a certificate for any subdomain has implications for other sibling domains, even without a wildcard certificate.
By default, web browsers are a lot less strict about Same Origin Policy for sibling domains, which enables a lot of web-based attacks (like CSRF and cookie stealing) if your able to hijack any subdomain