The Windows Server 2025 "Deny log on locally" user right on domain-joined member servers must be configured to prevent access from highly privileged domain accounts and from unauthenticated access on all systems.
Inappropriately granting user rights provides system, administrative, and other high-level capabilities.
The "Deny log on locally" user right defines accounts that are prevented from logging on interactively.
In an Active Directory Domain, denying logons to the Enterprise Admins and Domain Admins groups on lower-trust systems helps mitigate the risk of privilege escalation from credential theft attacks, which could lead to the compromise of an entire domain.
The Guests group must be assigned this right to prevent unauthenticated access.
How this relates to the STIG checklist: STIG vs SCAP benchmark.