Turn on certificate address mismatch warning: registry value WarnOnBadCertRecvingUserHKCU\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings

Policy ID: IZ_PolicyWarnCertMismatch
Scope: Computer Configuration, User Configuration
Supported on: At least Internet Explorer 8.0
Source: Administrative Templates (.admx) for Windows 11 2026 Update (26H2) (version 1.0)
Category: Windows Components › Internet Explorer › Internet Control Panel › Security Page

Registry

WarnOnBadCertRecving

REG_DWORDUserComputer

…\Software\Policies\Microsoft\Windows\CurrentVersion\Internet SettingsHKCU\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings Current key
HKLM\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings

Enabled value: 1

Apply with .reg · CMD · PowerShell

UserPer-account setting

Enabled

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings]
"WarnOnBadCertRecving"=dword:00000001

CMD · Enabled

reg add "HKCU\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings" /v "WarnOnBadCertRecving" /t REG_DWORD /d 1 /f

PowerShell · Enabled

New-Item -Path 'HKCU:\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings' -Force | Out-Null
New-ItemProperty -Path 'HKCU:\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings' -Name 'WarnOnBadCertRecving' -PropertyType DWord -Value 1 -Force | Out-Null

ComputerMachine-wide setting

Enabled

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings]
"WarnOnBadCertRecving"=dword:00000001

CMD · Enabled

reg add "HKLM\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings" /v "WarnOnBadCertRecving" /t REG_DWORD /d 1 /f

PowerShell · Enabled

New-Item -Path 'HKLM:\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings' -Force | Out-Null
New-ItemProperty -Path 'HKLM:\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings' -Name 'WarnOnBadCertRecving' -PropertyType DWord -Value 1 -Force | Out-Null