Mitigating Secure Boot Risks in 2026: A Comprehensive Guide

In June 2026 Secure boot certs start to going to expire for physical en virtual machines Servers en Clients. PS not only Windows but also Linux!!

PS. Make sure Client en Servers all installed with latest updates!!

Made a little Risk Assessment:

The expiration and replacement of Microsoft Secure Boot certificates pose a high risk to IT environments. If not properly managed, systems may fail to boot, updates may fail, and security risks may increase. This is particularly critical in automated and virtualized environments.

Key risks:

 Systems failing to boot after updates
 Incompatibility during OS or hypervisor upgrades
 Increased security risks due to outdated certificates

Recommended actions:

1.Update firmware and Secure Boot certificates
2.Test all workloads in a lab environment
3.Update golden images and automation pipelines

A phased rollout and proper validation are essential to prevent disruptions.

1. Scope

This document describes the risks, impact, and mitigations related to the expiration of Microsoft Secure Boot certificates in enterprise environments.

2. Affected Components

 Systems with UEFI firmware (Servers, Desktops, Virtual Machines)
 Microsoft UEFI CA certificates
 Operating Systems (Servers, Clients) (Windows, Linux)
 Automation tools like (Packer, MDT, SCCM)

3. Risk Analysis

Key risks:

 Incompatibility during upgrades
 Security vulnerabilities caused by outdated trust stores
 Errors in automation pipelines
 Firmware incompatibility

4. Risk Matrix

 Upgrade Issues: High
 Security Exposure: High
 Automation Failures: Medium
 Firmware Issues: High

5. Mitigations

 Update firmware on all systems
 Apply Microsoft Secure Boot updates
 Verify Event ID 1808
 Rebuild images with updated certificates
 Perform a phased rollout

6. Validation & Testing

 Test OS boot scenarios
 Validate Secure Boot status
 Verify automation pipelines

7. Conclusion

Changes to Secure Boot certificates must be treated as critical infrastructure updates. Proper preparation, testing, and phased implementation are essential to avoid disruptions.

.Microsoft has released patch’s for the following OS.

Windows 11 (23H2/24H2/25H2)
Windows Server 2016/2019/2022/2025.

VMware is creating a “Fix or Update” for this

* I did not test versions with extended support like Windows 2012 R2 and Windows 10.

Get your list with:
Get-VM | Where-Object { $_.ExtensionData.Config.Firmware -eq “efi” -and

$_.ExtensionData.Config.BootOptions.EfiSecureBootEnabled } | Select-Object Name,

   @{N=”OS”;E={$_.ExtensionData.Guest.GuestFullName}},  PowerState

There is a updated coming from VMware by Broadcom: Check this article:     @{N=”OS”;E={$_.ExtensionData.Guest.GuestFullName}},  PowerState

https://knowledge.broadcom.com/external/article/423893

Extra Info

Microsoft Info:

I hope that most People have Read: Windows Secure Boot certificate expiration and CA updates

and Secure Boot playbook for certificates expiring in 2026

Redhat:
Secure Boot Certificate Changes in 2026: Guidance for RHEL Environments

Broadcom:
Secure Boot Certificate Expirations and Update Failures in VMware Virtual Machines

Manual Update of the Secure Boot Platform Key in Virtual Machines





Simplified Fix Secure Boot Script for Easy VM Updates

I recently created 3 version of a FixSecureBoot script — a lightweight alternative inspired by the excellent work of haz-ard-9, the author of FixSecureBootBulk.ps1. Their script is powerful and absolutely the right choice if you rely on BitLocker or need a fully automated, safety‑first workflow.

However, at roughly 3,000 lines of code, the original script is understandably complex. It includes many checks and safeguards, which are great for production environments but made it harder for me to fully understand what was happening under the hood. I wanted something simpler, easier to read, and tailored to my own workflow.

So I took the time to study the original script, copied only the parts I needed, and built a much more compact version that gives me exactly the result I want — which show the verification step that every thing is correct updated.

What My Script Does

Here’s the full sequence of actions my simplified script performs:

1.Shuts down the VM
2.Creates a snapshot
3.Enables UEFI Setup Mode
4.Clears VMRAM (for older VMs)
5.Upgrades virtual hardware if the VM is below version 21 (vSphere 8)
6.Starts the VM and waits for VMware Tools
7.Checks that the guest OS is fully online
8.Downloads the required certificates (only once)
9.Uploads the two certificates to the VM if not exist
10.Installs the new boot certificates
11.Shuts down the VM and clears Setup Mode
12.Boots the VM and sets AvailableUpdates to 0x5944 (certs ready for install)
13.Reboots until AvailableUpdates becomes 0x4100 (may require multiple reboots)
14.Reboots and runs Secure-Boot-Update again
15.Reboots and runs Secure-Boot-Update again, then checks for Event ID 1808 (if found, everything is good)

I’ve tested this workflow successfully on:

 Windows 11 (23H2, 24H2, 25H2)
 Windows Server 2016, 2019, 2022, and 2025

Downloads
** link the links for downloading the original files from Microsoft Github page.

WindowsOEMDevicesPK.der
microsoft corporation kek 2k ca 2023.der

Rename microsoft corporation kek 2k ca 2023.der to kek2023.der

.

Current Limitation: Packer Integration

CLEAN PACKER BUILD IS NOT SAFE!! AFTER THE BUILD YOU NEED TO RUN FIX SECURE BOOT!!

I don’t yet have a complete fix for integrating this into a full Packer build. For now, I simply pre‑stage the certificates:

Build file:

provisioner “file” {

source = “./setup/SecurebootCert/”

destination = “C:/Windows/Temp”

}

I have build three versions:

Fix_Secure_Boot_Manual.ps1
Fix_Secure_Boot_Single.ps1
Fix_Secure_Boot_Multi.ps1

If you want a script that’s easier to read, easier to modify, and still gets the job done (as long as you’re not using BitLocker), this simplified version might be exactly what you need.

Let me know if you want me to share the script itself or write a follow‑up post about how it works internally.
.

.

Template Check if al ready Updated

If VM check if al ready updated

.

Run Script full from Template
.

Deploying Windows VMs with Terraform and Packer

A whale ago, I started using Packer for creating Windows Templates for using in my home lab.
I blogged about it here: Windows Server 2025 “Preview” deployment with Packer

So now I want to deploy a template with Terraform, which was created earlier by Packer.

First, we need to ensure we have the Terraform downloaded and the vSphere provider Initialized.

  1. Install Terraform: You can download it from the official Terraform website and follow the installation instructions for your operating system.

I made my life a little easier to create a PowerShell script that downloads the latest version: Download Terraform.ps1

  1. Initialize Your Terraform Configuration: Create a directory for your Terraform configuration files. Inside this directory, create a `main.tf` file (or any `.tf` file) where you will define your provider and other configurations.
    Define the vSphere Provider in Your main.tf: Add the following block to your Terraform configuration file to specify the use of the vSphere provider:

terraform {

  required_providers {

    vsphere = {

      source = “HashiCorp/vsphere”

      version = “> 2.11”

    }

  }

}

provider “vsphere” {

  user           = vcenter_username

  password       = vcenter_password

  vsphere_server = vcenter_server

  # If you have a self-signed cert

  allow_unverified_ssl = true

}

Replace ”vcenter_username”, ” vcenter_password” , ”vcenter_server” with your actual vSphere credentials and server address.

  1. Basic Terraform Commands

Terraform.ps1

# Go to the Terraform download folder

$terraformfolder = ‘d:\automation\terraform\’

Set-Location $terraformfolder

# Download Terraform plugins

.\terraform.exe init

# Test Run

.\terraform.exe plan

# Run Terraform

.\terraform.exe apply

# Clean Up what you created

.\terraform.exe Destroy

Initialize the Terraform Working Directory: Run the following command in your terminal from the directory where your Terraform configuration file is located:

terraform init

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This command will download the vSphere provider and initialize your Terraform working directory. It sets up and downloads the necessary provider plugins for Terraform to interact with vSphere.

Verify the Installation: After running `terraform init`, you should see output indicating that the vSphere provider has been successfully installed. You can now proceed to create Terraform configurations to manage your vSphere resources.

Deploy a Template VM within vSphere

In this example, we are deploying a VM running Windows Server 2022.

Terraform Module Structure

  1. variables.tf: Define the variables for the module.
  2. main.tf: Contains the main configuration for the VM.
  3. outputs.tf: Define the outputs for the module.

Variables.tf

variable “vsphere_user” {

  default     = “<your_vcenter_username_here>”

   description = “vSphere username to use to connect to the environment – Default: administrator@vsphere.local”

}

variable “vsphere_password” {

  default     = “<your_vcenter_password_here>”

  description = “vSphere vCenter password”

}

variable “vsphere_server” {

  default = “<your_vcenter_here>”

  description = “vSphere vCenter server”

}

variable “datacenter” {

  default = “<your_datacenter_here>”

  description = “vSphere datacenter”

}

variable “cluster” {

  default = “<your_cluster_here>”

  description = “vSphere cluster”

}

variable “network” {

  default = “<vcenter_network>”

  description = “vSphere network”

}

variable “datastore” {

  default = “<your_destination_datastore_>”

  description = “vSphere datastore”

}

variable “template” {

  default = “<your_template_name_here>”

  description = “Template VM”

}

variable “customization_specifications” {

  default = “<vcenter_customization_specifications>”

  description = “Customization Spec”

}

When you run “.\terraform plan” you do a test run to check your coding

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When you run “.\terraform apply” build your virtual machine

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Based on: https://vminfrastructure.com/2025/03/11/deploying-a-vm-using-terraform/

It works but it need some tweaking and fixing.

Adding a TPM2.0 security device does not work right now
Server 2025 customization does not work

Windows ADK 1703 and Windows 10 Creators Update 1703

Introduction

Microsoft have released both Windows 10 version 1703 and ADK 1703 last week, one is on MSDN the other on Microsoft’s download site.

Download the media

Two Know Issues:
OSD – App-V tools are missing in ADK 1703 when being installed on Windows Server 2016 (sometimes)

OS Deployment – Installing ADK 1703 on Windows Server 2016 could fail

WMI Filters for OS version

DESKTOPS

ANY WINDOWS DESKTOP OS

  • Any Windows Desktop OS – 32-bit
    select * from Win32_OperatingSystem WHERE ProductType = “1” AND NOT OSArchitecture = “64-bit”
  • Any Windows Desktop OS – 64-bit
    select * from Win32_OperatingSystem WHERE ProductType = “1” AND OSArchitecture = “64-bit”

WINDOWS 7

  • Windows 7
    select * from Win32_OperatingSystem WHERE Version like “6.1%” AND ProductType=”1″
  • Windows 7 – 32-bit
    select * from Win32_OperatingSystem WHERE Version like “6.1%” AND ProductType=”1″ AND NOT OSArchitecture = “64-bit”
  • Windows 7 – 64-bit
    select * from Win32_OperatingSystem WHERE Version like “6.1%” AND ProductType=”1″ AND OSArchitecture = “64-bit”

WINDOWS 8.1

  • Windows 8.1
    select * from Win32_OperatingSystem WHERE Version like “6.3%” AND ProductType=”1″
  • Windows 8.1 – 32-bit
    select * from Win32_OperatingSystem WHERE Version like “6.3%” AND ProductType=”1″ AND NOT OSArchitecture = “64-bit”
  • Windows 8.1 – 64-bit
    select * from Win32_OperatingSystem WHERE Version like “6.3%” AND ProductType=”1″ AND OSArchitecture = “64-bit”

WINDOWS 8.1

  • Windows 8.1
    select * from Win32_OperatingSystem WHERE Version like “6.3%” AND ProductType=”1″
  • Windows 8.1 – 32-bit
    select * from Win32_OperatingSystem WHERE Version like “6.3%” AND ProductType=”1″ AND NOT OSArchitecture = “64-bit”
  • Windows 8.1 – 64-bit
    select * from Win32_OperatingSystem WHERE Version like “6.3%” AND ProductType=”1″ AND OSArchitecture = “64-bit”

WINDOWS 10

  • Windows 10
    select * from Win32_OperatingSystem WHERE ‘Version like ‘10.0.%’ AND ProductType=”1″
  • Windows 10 – 32-bit
    select * from Win32_OperatingSystem WHERE Version like “10.0.% AND ProductType=”1” AND NOT OSArchitecture = “64-bit”
  • Windows 10 – 64-bit
    select * from Win32_OperatingSystem WHERE Version like “10.0.%””6.3%” AND ProductType=”1″ AND OSArchitecture = “64-bit”

SERVERS

ANY WINDOWS SERVER OS

  • Any Windows Server OS
    select * from Win32_OperatingSystem where (ProductType = “2”) OR (ProductType = “3”)
  • Any Windows Server OS – 32-bit
    select * from Win32_OperatingSystem where (ProductType = “2”) OR (ProductType = “3”) AND NOT OSArchitecture = “64-bit”
  • Any Windows Server OS – 64-bit
    select * from Win32_OperatingSystem where (ProductType = “2”) OR (ProductType = “3”) AND OSArchitecture = “64-bit”
  • Any Windows Server – Domain Controller
    select * from Win32_OperatingSystem where (ProductType = “2”)
  • Any Windows Server – Domain Controller – 32-bit
    select * from Win32_OperatingSystem where (ProductType = “2”) AND NOT OSArchitecture = “64-bit”
  • Any Windows Server – Domain Controller – 64-bit
    select * from Win32_OperatingSystem where (ProductType = “2”) AND OSArchitecture = “64-bit”
  • Any Windows Server – Non-Domain Controller
    select * from Win32_OperatingSystem where (ProductType = “3”)
  • Any Windows Server – Non- Domain Controller – 32-bit
    select * from Win32_OperatingSystem where (ProductType = “3”) AND NOT OSArchitecture = “64-bit”
  • Any Windows Server – Non-Domain Controller – 64-bit
    select * from Win32_OperatingSystem where (ProductType = “3”) AND OSArchitecture = “64-bit”

WINDOWS SERVER 2008 R2

  • Windows Server 2008 R2 – 64-bit – DC
    select * from Win32_OperatingSystem WHERE Version like “6.1%” AND ProductType=”2″
  • Windows Server 2008 R2 – 64-bit – non-DC
    select * from Win32_OperatingSystem WHERE Version like “6.1%” AND ProductType=”3″

WINDOWS SERVER 2012 R2

  • Windows Server 2012 R2 – 64-bit – DC
    select * from Win32_OperatingSystem WHERE Version like “6.3%” AND ProductType=”2″
  • Windows Server 2012 R2 – 64-bit – non-DC
    select * from Win32_OperatingSystem WHERE Version like “6.3%” AND ProductType=”3″

WINDOWS SERVER 2016

Windows 10 1607 Windows Update Change

For those of you who have started deploying Windows 10 1607, you might notice a change in the behavior of the Windows Update agent for PCs that are configured to pull updates from WSUS.  Instead of pulling the updates from WSUS, PCs may start grabbing them from peers on your network, leveraging the Delivery Optimization service for referrals to other PCs that have already obtained the content.  This change should generally help reduce the amount of network traffic being generated for both quality (monthly) updates and feature updates, offloading that traffic from the WSUS server.  It will add some additional traffic between each client PC and the Delivery Optimization service on the internet, as it has to talk to this internet-only service in order to get a list of peers.

If the Windows Update agent can’t talk to the Delivery Optimization service (due to firewall or proxy configurations), or if there are no peers able to provide the content, it will then go ahead and grab the content from the WSUS server.

There is a new Group Policy setting available if you want to disable this behavior, e.g. because you are already using BranchCache for peer-to-peer sharing.  To do this, you need to set the “Download Mode” policy under “Computer Configuration –> Administrative Templates –> Windows Components –> Delivery Optimization” to specify “Bypass” mode, which will result in the client always using BITS to transfer the content from WSUS (with BranchCache jumping in to provide the peer-to-peer capabilities through its integration with BITS):

image291

Of course to set this policy, you need the latest ADMX files, which can be downloaded from https://www.microsoft.com/en-us/download/details.aspx?id=53430 and are also included in Windows 10 1607 and Windows Server 2016.  (The “Bypass” setting wasn’t available in previous versions.)  See https://support.microsoft.com/en-us/kb/3087759 for details on how to update the Group Policy central store with these latest ADMX files, if you are using a central store.

Source: https://blogs.technet.microsoft.com/mniehaus/2016/08/08/using-wsus-with-windows-10-1607/

Free ebook: Deploying Windows 10: Automating deployment by using System Center Configuration Manager

We’re happy to announce the release of our newest free ebook, Deploying Windows 10: Automating deployment by using System Center Configuration Manager (ISBN 9781509301867), by Andre Della Monica, Russ Rimmerman, Alessandro Cesarini, and Victor Silveira.

5282.9781509301867_6F8A5B58

This ebook is also available for download at the Microsoft Virtual Academy (MVA).

Get a head start deploying Windows 10—with tips and best practices from experts in the field. This guide shows you how to deploy Windows 10 in an automated way without impacting end users by leveraging System Center Configuration Manager, which is the most used product to deploy Microsoft operating systems in the industry today.

DNS Best Practise

I thing i see at many client’s where i come is. Enable Automatic scavenging of stale records is forget to enable. This is a best practise. See: https://technet.microsoft.com/nl-nl/library/ff807390(v=ws.10).aspx

DC01

Use the Microsoft Best Practice Analyzer Winking smile

Powershell Smile

Set-DnsServerScavenging –ScavengingState $True –RefreshInterval  7:00:00:00 –NoRefreshInterval  7:00:00:00 –ScavengingInterval 7:00:00:00 –ApplyOnAllZones –Verbose

MS15-122 Security Update for Kerberos to Address Security Feature Bypass (Bitlocker)

This security update resolves a security feature bypass in Microsoft Windows. An attacker could bypass Kerberos authentication on a target machine and decrypt drives protected by BitLocker. The bypass can be exploited only if the target system has BitLocker enabled without a PIN or USB key, the computer is domain-joined, and the attacker has physical access to the computer.

This security update is rated Important for all supported editions of Windows. For more information, see the Affected Software section.

The update addresses the bypass by adding an additional authentication check that will run prior to a password change. For more information about the vulnerability, see theVulnerability Information section.

For more information about this update, see Microsoft Knowledge Base Article 3105256.

Administrative Templates (.admx) for Windows 10

Microsoft has released the Windows 10 Group Policy (.ADMX) templates . These .ADMX templates are released as a separate download package so you can manage group policy for Windows 10 clients more easily.

This new package includes additional (.ADMX) templates which are not included in the RTM version of Windows 10.

  1. DeliveryOptimization.admx
  2. fileservervssagent.admx
  3. gamedvr.admx
  4. grouppolicypreferences.admx
  5. grouppolicy-server.admx
  6. mmcsnapins2.admx
  7. terminalserver-server.admx
  8. textinput.admx
  9. userdatabackup.admx
  10. windowsserver.admx

To download the Windows 10 Group Policy (.ADMX) templates, please visit http://www.microsoft.com/en-us/download/details.aspx?id=48257

To review which settings are new in Windows 10, review the Windows 10 ADMX spreadsheet here:http://www.microsoft.com/en-us/download/details.aspx?id=25250

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