The Windows Server 2025 setting Microsoft network server: Digitally sign communications (always) must be configured to Enabled.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-278213SRG-OS-000423-GPOS-00187WN25-SO-000190SV-278213r1181345_rule2026-02-201

Description

The server message block (SMB) protocol provides the basis for many network operations. Digitally signed SMB packets aid in preventing man-in-the-middle attacks. If this policy is enabled, the SMB server will only communicate with an SMB client that performs SMB packet signing. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188

ℹ️ Check

If the following registry value does not exist or is not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LanManServer\Parameters\ Value Name: RequireSecuritySignature Value Type: REG_DWORD Value: 0x00000001 (1)

✔️ Fix

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> Microsoft network server: Digitally sign communications (always) to "Enabled".