System › Mitigation Options
Untrusted Font Blocking
Supported on At least Windows Server 2016, Windows 10
What it does
This security feature provides a global setting to prevent programs from loading untrusted fonts. Untrusted fonts are any font installed outside of the %windir%\Fonts directory. This feature can be configured to be in 3 modes: On, Off, and Audit. By default, it is Off and no fonts are blocked. If you aren't quite ready to deploy this feature into your organization, you can run it in Audit mode to see if blocking untrusted fonts causes any usability or compatibility issues.
What it writes
- Hive
- HKEY_LOCAL_MACHINE
- Registry key
SOFTWARE\Policies\Microsoft\Windows NT\MitigationOptions
Why it needs changes for Intune
- Policy references a Windows supportedOn definition.
- ADMX-INTUNE-WINDOWS-SUPPORTEDON-REFERENCE
In Intune
Native Intune setting: Yes — Policy CSP
./Device/Vendor/MSFT/Policy/Config/ADMX_GroupPolicy/FontMitigationADMX_GroupPolicy on Microsoft LearnADMX-backed: Windows ships this template, so it is set with the template's own values, without an import.Windows builds listed: 10.0.22000, 10.0.19043.1202, 10.0.19042.1202, 10.0.19041.1202.
From Microsoft's Policy CSP DDF files (DDF v2 Files, February 2026), read 18 Oct 2026.
Options
| Option | Type | Registry value | Allowed values |
|---|---|---|---|
| Mitigation OptionsRequiredDefault: Block untrusted fonts and log events | Drop-down list | MitigationOptions_FontBocking |
|
Configure and deploy
Choose a state and the option values; the output below is generated from the template for exactly that.
Enabled · Computer · template defaults
Registry file (.reg)
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\MitigationOptions]
"MitigationOptions_FontBocking"="1000000000000"
PowerShell
$ErrorActionPreference = 'Stop'
function Set-RegistryValue {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name,
[Parameter(Mandatory = $true)][string] $PropertyType,
[Parameter(Mandatory = $true)][object] $Value
)
if (-not (Test-Path -LiteralPath $Path)) {
New-Item -Path $Path -Force | Out-Null
}
New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}
function Remove-RegistryValue {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name
)
if (Test-Path -LiteralPath $Path) {
Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
}
}
function Clear-RegistryKeyValues {
param(
[Parameter(Mandatory = $true)][string] $Path
)
if (-not (Test-Path -LiteralPath $Path)) {
return
}
foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
}
}
# Policy: Untrusted Font Blocking
# Name: FontMitigation
# Scope: Machine
# State: Enabled
# Source: GroupPolicy.admx
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\MitigationOptions' -Name 'MitigationOptions_FontBocking' -PropertyType 'String' -Value '1000000000000'
These deployment candidates come from the ADMX template; they are separate from the native CSP mapping above.
- The OMA-URI is an inferred ADMX-backed Policy CSP candidate derived from the source ADMX file name and policy name.
- Some Microsoft policies use built-in Policy CSP pages whose area names don't match the ADMX file name, so verify the candidate against Microsoft Learn before deployment.
ADMX profile candidate (OMA-URI)
./Device/Vendor/MSFT/Policy/Config/ADMX_GroupPolicy/FontMitigationADMX SyncML candidate
<SyncML xmlns="SYNCML:SYNCML1.2">
<SyncBody>
<Replace>
<CmdID>1</CmdID>
<Item>
<Meta>
<Format>chr</Format>
<Type>text/plain</Type>
</Meta>
<Target>
<LocURI>./Device/Vendor/MSFT/Policy/Config/ADMX_GroupPolicy/FontMitigation</LocURI>
</Target>
<Data><enabled/>
<data id="FontMitigation_DL" value="1000000000000"/></Data>
</Item>
</Replace>
<Final/>
</SyncBody>
</SyncML>Intune remediation scripts
Detection
$ErrorActionPreference = 'Stop'
$reasons = [System.Collections.Generic.List[string]]::new()
function Test-RegistryValueExists {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name
)
if (-not (Test-Path -LiteralPath $Path)) {
return $false
}
return $null -ne (Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue)
}
function Test-RegistryValueEquals {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name,
[Parameter(Mandatory = $true)][string] $Kind,
[Parameter(Mandatory = $true)][object] $Expected
)
if (-not (Test-Path -LiteralPath $Path)) {
return $false
}
$valueObject = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue
if ($null -eq $valueObject) {
return $false
}
$actual = $valueObject.$Name
switch ($Kind) {
'String' { return [string]$actual -ceq [string]$Expected }
'ExpandString' { return [string]$actual -ceq [string]$Expected }
'DWord' { return [uint32]$actual -eq [uint32]$Expected }
'QWord' { return [uint64]$actual -eq [uint64]$Expected }
'MultiString' {
$actualArray = @($actual)
$expectedArray = @($Expected)
if ($actualArray.Count -ne $expectedArray.Count) { return $false }
for ($index = 0; $index -lt $actualArray.Count; $index++) {
if ([string]$actualArray[$index] -cne [string]$expectedArray[$index]) { return $false }
}
return $true
}
'Binary' {
$actualArray = [byte[]]$actual
$expectedArray = [byte[]]$Expected
if ($actualArray.Length -ne $expectedArray.Length) { return $false }
for ($index = 0; $index -lt $actualArray.Length; $index++) {
if ($actualArray[$index] -ne $expectedArray[$index]) { return $false }
}
return $true
}
default { return [string]$actual -ceq [string]$Expected }
}
}
# Policy: Untrusted Font Blocking
# Name: FontMitigation
# Scope: Machine
# State: Enabled
# Source: GroupPolicy.admx
$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\MitigationOptions' -Name 'MitigationOptions_FontBocking' -Kind 'String' -Expected '1000000000000'
if (-not $isMatch) {
$reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\MitigationOptions\MitigationOptions_FontBocking') | Out-Null
}
if ($reasons.Count -eq 0) {
Write-Output 'Compliant'
exit 0
}
$reasons | ForEach-Object { Write-Output $_ }
exit 1
Remediation
$ErrorActionPreference = 'Stop'
function Set-RegistryValue {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name,
[Parameter(Mandatory = $true)][string] $PropertyType,
[Parameter(Mandatory = $true)][object] $Value
)
if (-not (Test-Path -LiteralPath $Path)) {
New-Item -Path $Path -Force | Out-Null
}
New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}
function Remove-RegistryValue {
param(
[Parameter(Mandatory = $true)][string] $Path,
[Parameter(Mandatory = $true)][string] $Name
)
if (Test-Path -LiteralPath $Path) {
Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
}
}
function Clear-RegistryKeyValues {
param(
[Parameter(Mandatory = $true)][string] $Path
)
if (-not (Test-Path -LiteralPath $Path)) {
return
}
foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
}
}
# Policy: Untrusted Font Blocking
# Name: FontMitigation
# Scope: Machine
# State: Enabled
# Source: GroupPolicy.admx
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\MitigationOptions' -Name 'MitigationOptions_FontBocking' -PropertyType 'String' -Value '1000000000000'
History 5 retained releases
- 22H2 · 1.015 Jul 2024
- Already present in the first release ChangeIntel keeps.
4 later releases left it unchanged.
Template
- Internal name
FontMitigation- Namespace
Microsoft.Policies.GroupPolicy- Template file
GroupPolicy.admx- Release
- Windows 11 25H2 · 1.0 · file set
de4e49983ebd651f…
Definition, editor controls and support
Definition
<policy class="Machine" clientExtension="{2A8FDC61-2347-4C87-92F6-B05EB91A201A}" displayName="$(string.Font_List)" explainText="$(string.Font_List_Help)" key="SOFTWARE\Policies\Microsoft\Windows NT\MitigationOptions" name="FontMitigation" presentation="$(presentation.Font_List)" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.GroupPolicy:MitOptions" />
<supportedOn ref="Microsoft.Policies.Windows:SUPPORTED_Windows_10_0" />
<elements>
<enum id="FontMitigation_DL" required="true" valueName="MitigationOptions_FontBocking">
<item displayName="$(string.FontMitigation_On)">
<value>
<string>1000000000000</string>
</value>
</item>
<item displayName="$(string.FontMitigation_Off)">
<value>
<string>2000000000000</string>
</value>
</item>
<item displayName="$(string.FontMitigation_Audit)">
<value>
<string>3000000000000</string>
</value>
</item>
</enum>
</elements>
</policy>Editor controls
<presentation id="Font_List" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<dropdownList defaultItem="0" noSort="true" refId="FontMitigation_DL">Mitigation Options</dropdownList>
</presentation>Supported platforms and category
Microsoft.Policies.GroupPolicy:category:MitOptions
<category displayName="$(string.MitigationOptions)" name="MitOptions" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.Windows:System" />
</category>
Microsoft.Policies.Products:product:MicrosoftWindows
sha256:4b3cb6917b5e5b7cd142c0157f10882786b3e9ee67c29fd7b8f4c6cb2eec5fe7
Microsoft.Policies.Windows:category:System
<category displayName="$(string.System)" explainText="$(string.System_Help)" name="System" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Microsoft.Policies.Windows:definition:SUPPORTED_Windows_10_0
<definition displayName="$(string.SUPPORTED_Windows_10_0)" name="SUPPORTED_Windows_10_0" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<or>
<range minVersionIndex="13" ref="Microsoft.Policies.Products:MicrosoftWindows" />
</or>
</definition>
Microsoft.Policies.GroupPolicy:category:MitOptions
<category displayName="$(string.MitigationOptions)" name="MitOptions" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.Windows:System" />
</category>
<strings><string id="Microsoft.Policies.GroupPolicy:MitigationOptions">Mitigation Options</string></strings>
Microsoft.Policies.Products:product:MicrosoftWindows
<product displayName="$(string.MicrosoftWindows)" name="MicrosoftWindows" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<majorVersion displayName="$(string.MicrosoftWindows2000)" name="MicrosoftWindows2000" versionIndex="1">
<minorVersion displayName="$(string.MicrosoftWindows2000_RTM)" name="MicrosoftWindows2000_RTM" versionIndex="0" />
<minorVersion displayName="$(string.MicrosoftWindows2000_SP1)" name="MicrosoftWindows2000_SP1" versionIndex="1" />
<minorVersion displayName="$(string.MicrosoftWindows2000_SP2)" name="MicrosoftWindows2000_SP2" versionIndex="2" />
<minorVersion displayName="$(string.MicrosoftWindows2000_SP3)" name="MicrosoftWindows2000_SP3" versionIndex="3" />
<minorVersion displayName="$(string.MicrosoftWindows2000_SP4)" name="MicrosoftWindows2000_SP4" versionIndex="4" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsXP)" name="MicrosoftWindowsXP" versionIndex="2">
<minorVersion displayName="$(string.MicrosoftWindowsXP_RTM)" name="MicrosoftWindowsXP_RTM" versionIndex="0" />
<minorVersion displayName="$(string.MicrosoftWindowsXP_SP1)" name="MicrosoftWindowsXP_SP1" versionIndex="1" />
<minorVersion displayName="$(string.MicrosoftWindowsXP_SP2)" name="MicrosoftWindowsXP_SP2" versionIndex="2" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsServer2003)" name="MicrosoftWindowsServer2003" versionIndex="3">
<minorVersion displayName="$(string.MicrosoftWindowsServer2003_RTM)" name="MicrosoftWindowsServer2003_RTM" versionIndex="0" />
<minorVersion displayName="$(string.MicrosoftWindowsServer2003_SP1)" name="MicrosoftWindowsServer2003_SP1" versionIndex="1" />
<minorVersion displayName="$(string.MicrosoftWindowsServer2003_R2)" name="MicrosoftWindowsServer2003_R2" versionIndex="2" />
<minorVersion displayName="$(string.MicrosoftWindowsServer2003_SP2)" name="MicrosoftWindowsServer2003_SP2" versionIndex="3" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsVista)" name="MicrosoftWindowsVista" versionIndex="4">
<minorVersion displayName="$(string.MicrosoftWindowsVista_RTM)" name="MicrosoftWindowsVista_RTM" versionIndex="0" />
<minorVersion displayName="$(string.MicrosoftWindowsVista_SP1)" name="MicrosoftWindowsVista_SP1" versionIndex="1" />
</majorVersion>
<majorVersion displayName="$(string.WindowsServer2008)" name="WindowsServer2008" versionIndex="5">
<minorVersion displayName="$(string.WindowsServer2008_RTM)" name="WindowsServer2008_RTM" versionIndex="0" />
<minorVersion displayName="$(string.WindowsServer2008_R2)" name="WindowsServer2008_R2" versionIndex="1" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows7)" name="MicrosoftWindows7" versionIndex="6">
<minorVersion displayName="$(string.MicrosoftWindows7_RTM)" name="MicrosoftWindows7_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsServer8)" name="MicrosoftWindowsServer8" versionIndex="7">
<minorVersion displayName="$(string.MicrosoftWindowsServer8_RTM)" name="MicrosoftWindowsServer8_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows8)" name="MicrosoftWindows8" versionIndex="8">
<minorVersion displayName="$(string.MicrosoftWindows8_RTM)" name="MicrosoftWindows8_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows_RT)" name="MicrosoftWindows_RT" versionIndex="9">
<minorVersion displayName="$(string.MicrosoftWindows_RT_RTM)" name="MicrosoftWindows_RT_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsServer_6_3)" name="MicrosoftWindowsServer_6_3" versionIndex="10">
<minorVersion displayName="$(string.MicrosoftWindowsServer_6_3_RTM)" name="MicrosoftWindowsServer_6_3_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows_6_3)" name="MicrosoftWindows_6_3" versionIndex="11">
<minorVersion displayName="$(string.MicrosoftWindows_6_3_RTM)" name="MicrosoftWindows_6_3_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows_6_3_RT)" name="MicrosoftWindows_6_3_RT" versionIndex="12">
<minorVersion displayName="$(string.MicrosoftWindows_6_3_RT_RTM)" name="MicrosoftWindows_6_3_RT_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindowsServer_10_0)" name="MicrosoftWindowsServer_10_0" versionIndex="13">
<minorVersion displayName="$(string.MicrosoftWindowsServer_10_0_RTM)" name="MicrosoftWindowsServer_10_0_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows_10_0)" name="MicrosoftWindows_10_0" versionIndex="14">
<minorVersion displayName="$(string.MicrosoftWindows_10_0_RTM)" name="MicrosoftWindows_10_0_RTM" versionIndex="0" />
</majorVersion>
<majorVersion displayName="$(string.MicrosoftWindows_10_0_RT)" name="MicrosoftWindows_10_0_RT" versionIndex="15">
<minorVersion displayName="$(string.MicrosoftWindows_10_0_RT_RTM)" name="MicrosoftWindows_10_0_RT_RTM" versionIndex="0" />
</majorVersion>
</product>
<strings><string id="Microsoft.Policies.Products:MicrosoftWindows">Windows operating system</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000">Windows 2000 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_RTM">Windows 2000</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP1">Windows 2000 Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP2">Windows 2000 Service Pack 2</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP3">Windows 2000 Service Pack 3</string><string id="Microsoft.Policies.Products:MicrosoftWindows2000_SP4">Windows 2000 Service Pack 4</string><string id="Microsoft.Policies.Products:MicrosoftWindows7">Windows 7 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows7_RTM">Windows 7</string><string id="Microsoft.Policies.Products:MicrosoftWindows8">Windows 8 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows8_RTM">Windows 8</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003">Windows Server 2003 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_R2">Windows Server 2003 R2</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_RTM">Windows Server 2003</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_SP1">Windows Server 2003 Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer2003_SP2">Windows Server 2003 Service Pack 2</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer8">Windows Server 2012 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer8_RTM">Windows Server 2012</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_10_0">Windows Server 2016 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_10_0_RTM">Windows Server 2016</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_6_3">Windows Server 2012 R2 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsServer_6_3_RTM">Windows Server 2012 R2</string><string id="Microsoft.Policies.Products:MicrosoftWindowsVista">Windows Vista operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsVista_RTM">Windows Vista</string><string id="Microsoft.Policies.Products:MicrosoftWindowsVista_SP1">Windows Vista Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP">Windows XP operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP_RTM">Windows XP</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP_SP1">Windows XP Service Pack 1</string><string id="Microsoft.Policies.Products:MicrosoftWindowsXP_SP2">Windows XP Service Pack 2</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0">Windows 10 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0_RT">Windows 10 RT operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0_RTM">Windows 10</string><string id="Microsoft.Policies.Products:MicrosoftWindows_10_0_RT_RTM">Windows 10 RT</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3">Windows 8.1 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3_RT">Windows RT 8.1 operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3_RTM">Windows 8.1</string><string id="Microsoft.Policies.Products:MicrosoftWindows_6_3_RT_RTM">Windows RT 8.1</string><string id="Microsoft.Policies.Products:MicrosoftWindows_RT">Windows RT operating systems</string><string id="Microsoft.Policies.Products:MicrosoftWindows_RT_RTM">Windows RT</string><string id="Microsoft.Policies.Products:WindowsServer2008">Windows Server 2008 operating systems</string><string id="Microsoft.Policies.Products:WindowsServer2008_R2">Windows Server 2008 R2</string><string id="Microsoft.Policies.Products:WindowsServer2008_RTM">Windows Server 2008</string></strings>
Microsoft.Policies.Windows:category:System
<category displayName="$(string.System)" explainText="$(string.System_Help)" name="System" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Microsoft.Policies.Windows:System">System</string><string id="Microsoft.Policies.Windows:System_Help">Allows configuration of various system component settings.</string></strings>
Microsoft.Policies.Windows:definition:SUPPORTED_Windows_10_0
<definition displayName="$(string.SUPPORTED_Windows_10_0)" name="SUPPORTED_Windows_10_0" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<or>
<range minVersionIndex="13" ref="Microsoft.Policies.Products:MicrosoftWindows" />
</or>
</definition>
<strings><string id="Microsoft.Policies.Windows:SUPPORTED_Windows_10_0">At least Windows Server 2016, Windows 10</string></strings>