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Mozilla Firefox Group Policy settings

424 settings · 8.4 · 13 Oct 2026

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Mozilla › Firefox › Clear data when browser is closed

Active Logins

Computer and userIntune-readyF_SanitizeOnShutdown_Sessions

Supported on Firefox 74 or later, Firefox 68.6 ESR or later

What it does

If the policy is enabled, sessions are cleared when the browser is closed. If this policy is disabled or not configured, sessions are not cleared when the browser is closed.

What it writes

Hive
HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER
Registry key
Software\Policies\Mozilla\Firefox\SanitizeOnShutdown
Value name
Sessions
When enabled
DWORD 1
When disabled
DWORD 0

Configure and deploy

Choose a state; the output below is generated from the template for exactly that.

State
Apply to

Enabled · Computer · template defaults

Registry file (.reg)

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\Mozilla\Firefox\SanitizeOnShutdown]
"Sessions"=dword:00000001


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: Active Logins
# Name: F_SanitizeOnShutdown_Sessions
# Scope: Machine
# State: Enabled
# Source: firefox.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Mozilla\Firefox\SanitizeOnShutdown' -Name 'Sessions' -PropertyType 'DWord' -Value 1
  • 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_firefox/F_SanitizeOnShutdown_Sessions

ADMX 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_firefox/F_SanitizeOnShutdown_Sessions</LocURI>
        </Target>
        <Data>&lt;enabled/&gt;</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: Active Logins
# Name: F_SanitizeOnShutdown_Sessions
# Scope: Machine
# State: Enabled
# Source: firefox.admx

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Mozilla\Firefox\SanitizeOnShutdown' -Name 'Sessions' -Kind 'DWord' -Expected 1
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\Software\Policies\Mozilla\Firefox\SanitizeOnShutdown\Sessions') | 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: Active Logins
# Name: F_SanitizeOnShutdown_Sessions
# Scope: Machine
# State: Enabled
# Source: firefox.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Mozilla\Firefox\SanitizeOnShutdown' -Name 'Sessions' -PropertyType 'DWord' -Value 1

History 93 retained releases

  1. 7.220 Aug 2025
    • Description If the policy is enabled, sessions [added: are ]cleared when the browser is closed. If this policy is disabled or not configured, sessions[added: are] not cleared when the browser is closed.
      Whole description, marked

      If the policy is enabled, sessions [added: are ]cleared when the browser is closed. If this policy is disabled or not configured, sessions[added: are] not cleared when the browser is closed.

  2. 6.69 Jan 2025
    • Translations changed; choose a language above to compare its wording.
  3. 6.526 Nov 2024
    • Translations changed; choose a language above to compare its wording.
  4. 6.011 Jul 2024
    • Translations changed; choose a language above to compare its wording.
  5. 4.126 Jun 2023
    • Translations changed; choose a language above to compare its wording.
  6. 4.418 Oct 2022
    • Translations changed; choose a language above to compare its wording.
  7. 3.79 Mar 2022
    • Translations changed; choose a language above to compare its wording.
  8. 3.48 Dec 2021
    • Translations changed; choose a language above to compare its wording.
  9. 2.1019 Apr 2021
    • Translations changed; choose a language above to compare its wording.
  10. 2.823 Feb 2021
    • Translations changed; choose a language above to compare its wording.
  11. 1.174 Jun 2020
    • Translations changed; choose a language above to compare its wording.
  12. 1.165 May 2020
    • Translations changed; choose a language above to compare its wording.
  13. 1.158 Apr 2020
    • Translations changed; choose a language above to compare its wording.
  14. 1.1410 Mar 2020
    • Added in this release.

67 later releases left it unchanged.

Template

Internal name
F_SanitizeOnShutdown_Sessions
Namespace
Mozilla.Policies.Firefox
Template file
firefox.admx
Release
Mozilla Firefox 8.4 · file set a495190075c2a974…
Definition, editor controls and support

Definition

<policy class="Both" displayName="$(string.SanitizeOnShutdown_Sessions)" explainText="$(string.SanitizeOnShutdown_Sessions_Explain)" key="Software\Policies\Mozilla\Firefox\SanitizeOnShutdown" name="F_SanitizeOnShutdown_Sessions" valueName="Sessions" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Mozilla.Policies.Firefox:SanitizeOnShutdown" />
      <supportedOn ref="Mozilla.Policies.Firefox:SUPPORTED_FF74" />
      <enabledValue>
        <decimal value="1" />
      </enabledValue>
      <disabledValue>
        <decimal value="0" />
      </disabledValue>
    </policy>

Editor controls

Supported platforms and category

Mozilla.Policies.Firefox:category:SanitizeOnShutdown
<category displayName="$(string.SanitizeOnShutdown_group)" name="SanitizeOnShutdown" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Mozilla.Policies.Firefox:firefox" />
    </category>
Mozilla.Policies.Firefox:category:firefox
<category displayName="$(string.firefox)" name="firefox" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Mozilla.Policies:Cat_Mozilla" />
    </category>
Mozilla.Policies.Firefox:definition:SUPPORTED_FF74
<definition displayName="$(string.SUPPORTED_FF74)" name="SUPPORTED_FF74" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Mozilla.Policies:category:Cat_Mozilla
<category displayName="$(string.mozilla)" name="Cat_Mozilla" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Mozilla.Policies.Firefox:category:SanitizeOnShutdown
<category displayName="$(string.SanitizeOnShutdown_group)" name="SanitizeOnShutdown" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Mozilla.Policies.Firefox:firefox" />
    </category>
<strings><string id="Mozilla.Policies.Firefox:SanitizeOnShutdown_group">Clear data when browser is closed</string></strings>
Mozilla.Policies.Firefox:category:firefox
<category displayName="$(string.firefox)" name="firefox" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Mozilla.Policies:Cat_Mozilla" />
    </category>
<strings><string id="Mozilla.Policies.Firefox:firefox">Firefox</string></strings>
Mozilla.Policies.Firefox:definition:SUPPORTED_FF74
<definition displayName="$(string.SUPPORTED_FF74)" name="SUPPORTED_FF74" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Mozilla.Policies.Firefox:SUPPORTED_FF74">Firefox 74 or later, Firefox 68.6 ESR or later</string></strings>
Mozilla.Policies:category:Cat_Mozilla
<category displayName="$(string.mozilla)" name="Cat_Mozilla" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Mozilla.Policies:mozilla">Mozilla</string></strings>
ChangeIntel

An IT change radar: releases, security, known issues, retirements, documentation changes, and service status from public sources. Every item links to supporting evidence; dates and statuses can change after they are read.

Sources read 20 Oct 18:51 UTC · 258 of 260 readable · 256 fully read · documentation 416/439 current