Topic starter
23/06/2026 7:12 pm
TL;DR: Dangling DNS records can leave trusted subdomains pointing at assets the organisation no longer controls, DigiCert found. DNS governance has to track service retirement closely, or stale records can turn a legitimate name into a takeover point.
Editorial analysis by NHI Mgmt Group, based on content published by DigiCert: “Dangling DNS Records and the Risk of Domain Hijacking”.
Key questions
Q: Why do dangling DNS records create a real subdomain takeover risk?
A: Dangling DNS records create risk because they still direct traffic to a name that no longer points to an active backend.
Q: How should security teams prevent dangling DNS records from creating takeover risk?
A: Security teams should tie DNS record retirement to the same workflow that decommissions the underlying service.
Q: What breaks when a DNS record outlives the service it points to?
A: The trust chain breaks because the subdomain still appears legitimate even though the organisation no longer controls the destination behind it.
Practitioner guidance
- Audit abandoned DNS records Review CNAME and A records that point to cloud services, SaaS properties, or storage resources no longer in active use.
- Tie DNS cleanup to decommissioning Require DNS retirement as part of every service shutdown, cloud migration, and vendor offboarding workflow so names do not outlive ownership.
- Monitor for takeover indicators Watch for resolution failures, unusual record behaviour, and sudden traffic spikes on legacy subdomains, then investigate whether the target asset has been deleted or abandoned.
Bottom line: Dangling DNS records are dangerous because they let a trusted subdomain keep pointing at something the organisation no longer controls.
Glossary terms: Dangling DNS Record, Subdomain Takeover, DNS Hygiene
Explore further
View Full Forum → | NHI Foundation Course → | Our Services → | Read the full analysis →
This topic was modified 12 hours ago by NHI Mgmt Group
25/06/2026 3:05 am
Dangling DNS records are an ownership problem before they are a technical one. The record still resolves, but the organisation has already lost control of the destination it points to. That creates a governance gap between service retirement and DNS cleanup, and attackers exploit that gap by claiming what the organisation forgot to revoke.
A few things that frame the scale:
- 92% of organisations expose NHIs to third parties, raising concerns about supply chain security, according to the Ultimate Guide to NHIs.
A question worth separating out:
Q: What should teams do when a subdomain still has business value after a migration?
A: They should repoint the record to the new approved destination or set up a controlled redirect if the name must remain visible to users. The key is to preserve intent without leaving the old target claimable. If the record no longer serves a live purpose, retirement is the safer option.
👉 Read our full editorial: Dangling DNS records let abandoned subdomains become takeover risk
This post was modified 12 hours ago by NHI Mgmt Group