Subdomain takeover of resources.hackerone.com

How it was found

Hello,

I just went to https://resources.hackerone.com/ and it shows an error "Non-hub domain, The URL you've accessed does not provide a hub. Please check the URL and try again." also i've checked the CNAME is poiting to read.uberflip.com which means if it is not added it can be added to any account, as Uberflip documentation suggests that after your subdomain is pointing to their CNAME which is read.uberflip.com, your subdomain should be added to your account so it shows the URL you chose for your hub. As i couldn't signup on their website to test due to signup problems, i just wanted your confirmation whether this subdomain is added in uberflip account or not. If not then claim it otherwise any one can add or claim this to their Uberflip account

Impact

Subdomain takeover.