Lifecycle mismatch is when a cloud service or other asset is decommissioned, but its DNS record or related hostname is left behind. The result is a dangling reference: the name still exists, but the intended resource no longer does.
This matters because DNS often outlives the service it points to. Attackers search for these stale records during reconnaissance and may abuse them for subdomain takeover, phishing, or traffic interception if provider rules let the target be claimed again. Defenders reduce the risk by linking DNS cleanup to deprovisioning, maintaining accurate asset inventory, and scanning for orphaned CNAMEs and other aliases before old names become attack surfaces.