Enable insecure guest logons
Verified with Windows 11 25H2 — updated on July 30, 2026
Supported on: At least Windows Server 2016, Windows 10
Path in the GPO console
Computer Configuration\Administrative Templates\Network\Lanman Workstation Description
This policy setting determines if the SMB client will allow insecure guest logons to an SMB server. If you enable this policy setting or if you do not configure this policy setting, the SMB client will allow insecure guest logons. If you disable this policy setting, the SMB client will reject insecure guest logons. If you enable signing, the SMB client will reject insecure guest logons. Insecure guest logons are used by file servers to allow unauthenticated access to shared folders. While uncommon in an enterprise environment, insecure guest logons are frequently used by consumer Network Attached Storage (NAS) appliances acting as file servers. Windows file servers require authentication and do not use insecure guest logons by default. Since insecure guest logons are unauthenticated, important security features such as SMB Signing and SMB Encryption are disabled. As a result, clients that allow insecure guest logons are vulnerable to a variety of man-in-the-middle attacks that can result in data loss, data corruption, and exposure to malware. Additionally, any data written to a file server using an insecure guest logon is potentially accessible to anyone on the network. Microsoft recommends disabling insecure guest logons and configuring file servers to require authenticated access."
Registry
Software\Policies\Microsoft\Windows\LanmanWorkstation Value name: AllowInsecureGuestAuth
Enabled: AllowInsecureGuestAuth = 1
Disabled: AllowInsecureGuestAuth = 0
MDM / Intune (CSP)
./Device/Vendor/MSFT/Policy/Config/LanmanWorkstation/EnableInsecureGuestLogons Microsoft Learn documentation Mapping data: Microsoft Learn (CC BY 4.0)
CSP values
-
0 (Default)- Disabled. -
1- Enabled.
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: Enable insecure guest logons
; State: Enabled
; Supported on: At least Windows Server 2016, Windows 10
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\LanmanWorkstation]
"AllowInsecureGuestAuth"=dword:00000001More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Enable insecure guest logons
# State: Enabled
# Supported on: At least Windows Server 2016, Windows 10
$path = 'HKLM:\Software\Policies\Microsoft\Windows\LanmanWorkstation'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'AllowInsecureGuestAuth' -Value 1 -Type DWordIntune XML
OMA-URI: ./Device/Vendor/MSFT/Policy/Config/LanmanWorkstation/EnableInsecureGuestLogons
Data type: String
Value:
<enabled/>Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Enable insecure guest logons
# State: Enabled
# Supported on: At least Windows Server 2016, Windows 10
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LanmanWorkstation' -Name 'AllowInsecureGuestAuth' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Enable insecure guest logons
# State: Enabled
# Supported on: At least Windows Server 2016, Windows 10
$path = 'HKLM:\Software\Policies\Microsoft\Windows\LanmanWorkstation'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'AllowInsecureGuestAuth' -Value 1 -Type DWordSCCM scripts
# Exported from gporais.com
# Policy: Enable insecure guest logons
# State: Enabled
# Supported on: At least Windows Server 2016, Windows 10
# 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: Enable insecure guest logons
# State: Enabled
# Supported on: At least Windows Server 2016, Windows 10
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Policies\Microsoft\Windows\LanmanWorkstation' -Name 'AllowInsecureGuestAuth' -Expected 1 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Enable insecure guest logons
# State: Enabled
# Supported on: At least Windows Server 2016, Windows 10
$path = 'HKLM:\Software\Policies\Microsoft\Windows\LanmanWorkstation'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'AllowInsecureGuestAuth' -Value 1 -Type DWordBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.