Make Access-Control-Allow-Methods matching in CORS preflight spec conformant
Verified with Microsoft Edge 152.0.4191.53 — updated on July 10, 2026
Supported on: Microsoft Edge version 123, Windows 7 or later
Path in the GPO console
Computer Configuration\Administrative Templates\Microsoft Edge\Network settings User Configuration\Administrative Templates\Microsoft Edge\Network settings Description
This policy controls whether request methods are uppercased when matching with Access-Control-Allow-Methods response headers in CORS preflight. If you disable this policy, request methods are uppercased. This is the behavior on or before Microsoft Edge 108. If you enable or don't configure this policy, request methods aren't uppercased, unless matching case-insensitively with DELETE, GET, HEAD, OPTIONS, POST, or PUT. This would reject fetch(url, {method: 'Foo'}) + "Access-Control-Allow-Methods: FOO" response header, and would accept fetch(url, {method: 'Foo'}) + "Access-Control-Allow-Methods: Foo" response header. Note: request methods "post" and "put" aren't affected, while "patch" is affected. This policy is intended to be temporary and will be removed in the future.
Registry
Software\Policies\Microsoft\Edge Software\Policies\Microsoft\Edge Value name: AccessControlAllowMethodsInCORSPreflightSpecConformant
Enabled: AccessControlAllowMethodsInCORSPreflightSpecConformant = 1
Disabled: AccessControlAllowMethodsInCORSPreflightSpecConformant = 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. ⓘ
Applying both scopes creates an ambiguous configuration (computer takes precedence over user). Only do this intentionally.
.reg file
Windows Registry Editor Version 5.00
; Exported from gporais.com
; Policy: Make Access-Control-Allow-Methods matching in CORS preflight spec conformant
; State: Enabled
; Scope: Computer (HKLM)
; Supported on: Microsoft Edge version 123, Windows 7 or later
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Edge]
"AccessControlAllowMethodsInCORSPreflightSpecConformant"=dword:00000001More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Make Access-Control-Allow-Methods matching in CORS preflight spec conformant
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 123, Windows 7 or later
$path = 'HKLM:\Software\Policies\Microsoft\Edge'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'AccessControlAllowMethodsInCORSPreflightSpecConformant' -Value 1 -Type DWordIntune XML
No direct Policy CSP / OMA-URI mapping for this policy. Use the Intune Remediation tab, or ingest the ADMX in Intune.Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Make Access-Control-Allow-Methods matching in CORS preflight spec conformant
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 123, Windows 7 or later
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Edge' -Name 'AccessControlAllowMethodsInCORSPreflightSpecConformant' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Make Access-Control-Allow-Methods matching in CORS preflight spec conformant
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 123, Windows 7 or later
$path = 'HKLM:\Software\Policies\Microsoft\Edge'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'AccessControlAllowMethodsInCORSPreflightSpecConformant' -Value 1 -Type DWordSCCM scripts
# Exported from gporais.com
# Policy: Make Access-Control-Allow-Methods matching in CORS preflight spec conformant
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 123, Windows 7 or later
# 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: Make Access-Control-Allow-Methods matching in CORS preflight spec conformant
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 123, Windows 7 or later
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Edge' -Name 'AccessControlAllowMethodsInCORSPreflightSpecConformant' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Make Access-Control-Allow-Methods matching in CORS preflight spec conformant
# State: Enabled
# Scope: Computer (HKLM)
# Supported on: Microsoft Edge version 123, Windows 7 or later
$path = 'HKLM:\Software\Policies\Microsoft\Edge'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'AccessControlAllowMethodsInCORSPreflightSpecConformant' -Value 1 -Type DWordBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.