Certificates can include several DNS names in their Subject Alternative Name list. SSLBoard uses those names to identify adjacent domains associated with the observed certificates.
What the relationship means
An adjacent domain shares certificate-name evidence with the scanned domain. It may belong to another part of your organization, an earlier deployment, or a shared hosting arrangement. The relationship alone does not prove common ownership, an active service, or a vulnerability.
For example, a certificate that contains both www.example.com and a name under another domain supplies a relationship worth reviewing. It does not establish that the other domain has received the same scan coverage.
Scope stays with the submitted domain
Adjacent domains are context, not an automatic extension of the report’s TLS assessment. If you need a report for another domain, assess it separately and read its own discovered-host inventory and evidence.
A wildcard in a certificate does not enumerate all names below it. An empty adjacent-domain list likewise does not prove that the organization has no other domains.
Review an unexpected relationship
Check the certificate names and issuer, then ask the responsible operator whether the shared certificate is intentional. If a deployment or certificate changes, retest to see what is now served. Use discovery and coverage to distinguish a historical name from a live service.