Require strict KDC validation
Verified with Windows 11 25H2 — updated on July 30, 2026
Supported on: At least Windows Vista
Path in the GPO console
Computer Configuration\Administrative Templates\System\Kerberos Description
This policy setting controls the Kerberos client's behavior in validating the KDC certificate for smart card and system certificate logon. If you enable this policy setting, the Kerberos client requires that the KDC's X.509 certificate contains the KDC key purpose object identifier in the Extended Key Usage (EKU) extensions, and that the KDC's X.509 certificate contains a dNSName subjectAltName (SAN) extension that matches the DNS name of the domain. If the computer is joined to a domain, the Kerberos client requires that the KDC's X.509 certificate must be signed by a Certificate Authority (CA) in the NTAuth store. If the computer is not joined to a domain, the Kerberos client allows the root CA certificate on the smart card to be used in the path validation of the KDC's X.509 certificate. If you disable or do not configure this policy setting, the Kerberos client requires only that the KDC certificate contain the Server Authentication purpose object identifier in the EKU extensions which can be issued to any server.
Registry
Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\Parameters Value name: KdcValidation
Enabled: KdcValidation = 2
Disabled: KdcValidation = 0
MDM / Intune (CSP)
./Device/Vendor/MSFT/Policy/Config/Kerberos/RequireStrictKDCValidation Microsoft Learn documentation Mapping data: Microsoft Learn (CC BY 4.0)
Export Builder
BETAConfigure the state, scope and options, then generate .reg, PowerShell, Intune and SCCM outputs — or add the setting to a multi-setting collection.
These exports write the registry — this is not a managed GPO. ⓘ
.reg file
Windows Registry Editor Version 5.00
; Exported from gporais.com
; Policy: Require strict KDC validation
; State: Enabled
; Supported on: At least Windows Vista
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\Parameters]
"KdcValidation"=dword:00000002More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Require strict KDC validation
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\Parameters'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'KdcValidation' -Value 2 -Type DWordIntune XML
OMA-URI: ./Device/Vendor/MSFT/Policy/Config/Kerberos/RequireStrictKDCValidation
Data type: String
Value:
<enabled/>Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Require strict KDC validation
# State: Enabled
# Supported on: At least Windows Vista
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\Parameters' -Name 'KdcValidation' -Expected 2 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Require strict KDC validation
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\Parameters'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'KdcValidation' -Value 2 -Type DWordSCCM scripts
# Exported from gporais.com
# Policy: Require strict KDC validation
# State: Enabled
# Supported on: At least Windows Vista
# SCCM Configuration Item guidance:
# Create a Configuration Item of type "Setting: Script".
# Discovery script: use the Detection script below.
# Remediation script: use the Remediation script below.
# Compliance rule: the Discovery script output equals 'Compliant'.
# === Detection script ===
# Exported from gporais.com
# Policy: Require strict KDC validation
# State: Enabled
# Supported on: At least Windows Vista
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\Parameters' -Name 'KdcValidation' -Expected 2 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Require strict KDC validation
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\Kerberos\Parameters'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'KdcValidation' -Value 2 -Type DWordBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.