Microsoft Edge
Specifies whether SharedArrayBuffers can be used in a non cross-origin-isolated context
Supported on Microsoft Edge version 92, Windows 7 or later
What it does
Specifies whether SharedArrayBuffers can be used in a non-cross-origin-isolated context. A SharedArrayBuffer is a binary data buffer that's used to create views on shared memory. SharedArrayBuffers have a memory access vulnerability in several popular CPUs. If you enable this policy, sites are allowed to use SharedArrayBuffers with no restrictions. If you disable or don't configure this policy, sites are allowed to use SharedArrayBuffers only when cross-origin isolated. Microsoft Edge requires cross-origin isolation when using SharedArrayBuffers from Microsoft Edge version 91 onward for Web Compatibility reasons.
What it writes
- Hive
- HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER
- Registry key
Software\Policies\Microsoft\Edge- Value name
SharedArrayBufferUnrestrictedAccessAllowed- When enabled
- DWORD 1
- When disabled
- DWORD 0
Security baselines
Microsoft's Microsoft Edge v151 Security Baseline sets this to Disabled, in its GPO “MSFT Edge Version 151 - Computer”.
- Policy value SharedArrayBufferUnrestrictedAccessAllowed
- Sets SharedArrayBufferUnrestrictedAccessAllowed to 0 (REG_DWORD).
Read from the registry.pol files in the baselines' GPO backups, downloaded from Microsoft's Security Compliance Toolkit. All baselines
Configure and deploy
Choose a state; 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\Edge]
"SharedArrayBufferUnrestrictedAccessAllowed"=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: Specifies whether SharedArrayBuffers can be used in a non cross-origin-isolated context
# Name: SharedArrayBufferUnrestrictedAccessAllowed
# Scope: Machine
# State: Enabled
# Source: msedge.admx
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge' -Name 'SharedArrayBufferUnrestrictedAccessAllowed' -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_msedge/SharedArrayBufferUnrestrictedAccessAllowedADMX 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_msedge/SharedArrayBufferUnrestrictedAccessAllowed</LocURI>
</Target>
<Data><enabled/></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: Specifies whether SharedArrayBuffers can be used in a non cross-origin-isolated context
# Name: SharedArrayBufferUnrestrictedAccessAllowed
# Scope: Machine
# State: Enabled
# Source: msedge.admx
$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge' -Name 'SharedArrayBufferUnrestrictedAccessAllowed' -Kind 'DWord' -Expected 1
if (-not $isMatch) {
$reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge\SharedArrayBufferUnrestrictedAccessAllowed') | Out-Null
}
if ($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 $propertyName -Force -ErrorAction SilentlyContinue
}
}
# Policy: Specifies whether SharedArrayBuffers can be used in a non cross-origin-isolated context
# Name: SharedArrayBufferUnrestrictedAccessAllowed
# Scope: Machine
# State: Enabled
# Source: msedge.admx
Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge' -Name 'SharedArrayBufferUnrestrictedAccessAllowed' -PropertyType 'DWord' -Value 1
History 37 retained releases
- 150.0.4078.8016 Jul 2026
- Already present in the first release ChangeIntel keeps.
36 later releases left it unchanged.
Template
- Internal name
SharedArrayBufferUnrestrictedAccessAllowed- Namespace
Microsoft.Policies.Edge- Template file
msedge.admx- Release
- Microsoft Edge 155.0.4283.62 · file set
0a733b0040dbbf02…
Definition, editor controls and support
Definition
<policy class="Both" displayName="$(string.SharedArrayBufferUnrestrictedAccessAllowed)" explainText="$(string.SharedArrayBufferUnrestrictedAccessAllowed_Explain)" key="Software\Policies\Microsoft\Edge" name="SharedArrayBufferUnrestrictedAccessAllowed" presentation="$(presentation.SharedArrayBufferUnrestrictedAccessAllowed)" valueName="SharedArrayBufferUnrestrictedAccessAllowed" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
<parentCategory ref="Microsoft.Policies.Edge:microsoft_edge" />
<supportedOn ref="Microsoft.Policies.Edge:SUPPORTED_WIN7_V92" />
<enabledValue>
<decimal value="1" />
</enabledValue>
<disabledValue>
<decimal value="0" />
</disabledValue>
</policy>Editor controls
<presentation id="SharedArrayBufferUnrestrictedAccessAllowed" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />Supported platforms and category
Microsoft.Policies.Edge:category:microsoft_edge
<category displayName="$(string.microsoft_edge)" name="microsoft_edge" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Microsoft.Policies.Edge:definition:SUPPORTED_WIN7_V92
<definition displayName="$(string.SUPPORTED_WIN7_V92)" name="SUPPORTED_WIN7_V92" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Microsoft.Policies.Edge:category:microsoft_edge
<category displayName="$(string.microsoft_edge)" name="microsoft_edge" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Microsoft.Policies.Edge:microsoft_edge">Microsoft Edge</string></strings>
Microsoft.Policies.Edge:definition:SUPPORTED_WIN7_V92
<definition displayName="$(string.SUPPORTED_WIN7_V92)" name="SUPPORTED_WIN7_V92" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Microsoft.Policies.Edge:SUPPORTED_WIN7_V92">Microsoft Edge version 92, Windows 7 or later</string></strings>