Delete the CNAME that points at an unregistered domain

Why it matters

A subdomain's CNAME points at a domain nobody has registered, so anyone can register it and take over what visitors see on your subdomain. Delete the record now, since it already does nothing useful.

The fix

1. Find the CNAME in the DNS zone, using the name from the finding.
2. Delete it. The target does not exist, so the subdomain does not work now anyway. If you meant to keep it, point it at a name you control.
3. If the target domain was one of yours that expired, renew or re-register it only if you still need it, and make sure nobody else got it first.
4. Search the zone for other records that point at the same target or at similar names, and remove those too.
5. Check that no cookies, links, emails or services rely on that subdomain, and confirm it now returns no record.

# replace sub with the subdomain named in the finding
dig CNAME sub.example.com +short
dig sub.example.com

The examples use example.com. Replace it with your own domain.

Read the documentation ↗(opens in a new tab)

Related

• Reported by the Dangling CNAMEs check
• Remove or reclaim the CNAME to a deprovisioned service
• Move the CNAME to an internal name out of public DNS
• Delete the CNAME that points at a name that does not exist
• Fix the wildcard CNAME that points at a missing name