SecDNS
DNS Hygiene2026-01-145 min read

How to Avoid Subdomain Takeovers

Common dangling DNS pitfalls and how to prevent them.

Dangling CNAMEs are the #1 cause of subdomain takeovers.

When a DNS record points to a deprovisioned resource, attackers can claim it.

Regularly inventory subdomains and remove unused records.

Automate checks for NXDOMAIN targets and orphaned cloud resources.