When DNS entries point to conf.researchr.org (CNAME record typically), it will load the conf.researchr.org landing page. The browser will show a security warning when the domain is not on the certificate yet (because it isn’t mapped in the URL routing of the platform yet).
However if users, or any client in general, will ignore the certificate error, they will still be able to load any conference website instance using the custom domain as if they were browsing the platform using conf.researchr.org domain name. This results in n mirrors of conf.researchr.org, where n is the number of unmapped domain names.

Proposed fix: redirect to https://conf.researchr.org homepage when a domain name does not appear in the URL mapping (yet).

Submitted by Elmer van Chastelet on 13 November 2023 at 13:59