Tag: windows 10

If March 2026 was a marathon of infrastructure updates, April is a massive avalanche of patches.

Microsoft’s fourth Patch Tuesday of 2026 has arrived, addressing a massive 165 vulnerabilities in total. The sheer volume demands attention. It contains two 0-day vulnerabilities — one of which is actively exploited in the wild — and eight critical flaws affecting a wide range of products, including Office, SharePoint, Microsoft Defender, and Azure.

Here is the breakdown of what you need to know, what to patch first, and what might break.

The April 2026 Patch Day overview

Executive Summary

• Release Date: April 14, 2026
• Total Vulnerabilities: 165
• Critical Vulnerabilities: 8
• Zero-Days: 2 (SharePoint [Actively Exploited], Microsoft Defender [Publicly Disclosed])

Key Action Item: Administrators must prioritize patching internet-facing SharePoint servers due to the actively exploited spoofing zero-day. Simultaneously, network infrastructure and Active Directory components need immediate updates to mitigate several highly critical Remote Code Execution vulnerabilities.

Important Patches

• CVE-2026-32201 — Microsoft Office SharePoint Spoofing Vulnerability
• CVE-2026-33825 — Microsoft Defender Elevation of Privilege Vulnerability
• CVE-2026-33824 — Windows Internet Key Exchange (IKE) Extension Remote Code Execution Vulnerability
• CVE-2026-33827 — Windows TCP/IP Remote Code Execution Vulnerability
• CVE-2026-33826 — Windows Active Directory Remote Code Execution Vulnerability
• CVE-2026-23666 — .NET Denial of Service Vulnerability

Cumulative Updates

Deep Dive: The Critical Vulnerabilities

Microsoft confirmed that it patched two 0-day vulnerabilities this Patch Day and several critical remote code execution flaws.

Here is the critical overview:

CVE-2026-32201 (Microsoft Office SharePoint Spoofing Vulnerability)

This actively exploited zero-day allows an unauthorized attacker to perform spoofing over a network due to improper input validation in Microsoft Office SharePoint. An attacker who successfully exploits this can view sensitive information and make changes to disclosed information.

CVE-2026-33825 (Microsoft Defender Elevation of Privilege Vulnerability)

A publicly disclosed zero-day flaw in Microsoft Defender that allows privilege escalation to SYSTEM privileges. Microsoft has addressed the flaw in the Microsoft Defender Antimalware Platform update version 4.18.26050.3011, which should be downloaded to (most) systems automatically.

CVE-2026-33824 (Windows Internet Key Exchange (IKE) Extension RCE)

A critical double-free vulnerability in the Windows IKE extension. An unauthenticated attacker can send specially crafted packets to a Windows machine with IKE version 2 enabled to potentially achieve remote code execution. If IKE is not in use, blocking inbound traffic on UDP ports 500 and 4500 acts as a mitigation.

CVE-2026-33827 (Windows TCP/IP Remote Code Execution)

A critical race condition vulnerability in Windows TCP/IP that can result in remote code execution. An unauthenticated actor can send specially crafted IPv6 packets to a Windows node where IPSec is enabled to potentially achieve RCE.

CVE-2026-33826 (Windows Active Directory Remote Code Execution)

A critical improper input validation flaw in Windows Active Directory. It allows an authenticated attacker to execute code over an adjacent network.

First Steps: Your Patch Tuesday Strategy

• Prioritize the SharePoint zero-day
• Address network and directory risks
• Update Office installations

If you’ve ever felt completely lost in the web of Windows testing tiers or frustrated by slow A/B feature rollouts, relief may finally have arrived.

Microsoft announced a big overhaul of the Windows Insider Program this week designed to simplify how users test development builds of the operating system.

The company is cutting down the channel list to just two primary ones — Beta and Experimental — and is finally changing how experimental features land on test systems.

Here is a breakdown of the major changes:

• Two Streamlined Channels: The previously confusing multi-tier system is being condensed into just two primary tracks: Experimental (which replaces the Dev and Canary channels) and Beta (for features that are closer to being ready for the public).
• The End of A/B Testing: Microsoft is officially dropping its Controlled Feature Rollout (CFR) system for Beta channel participants. This means no more waiting in the dark while other testers randomly receive new features before you do.
• Manual Feature Flags: You are finally getting direct control over your testing experience. Moving forward, Insiders can manually toggle new features on or off directly within Windows Settings as soon as they are documented in the changelogs.
• No More “Clean Install” Trap: Historically, leaving the Insider program or dropping down to a more stable channel often required a complete, data-wiping OS reinstall. Microsoft is fixing this by allowing in-place upgrades (IPU), meaning you can transition channels or exit the program while keeping your files and apps intact.
• Clearer Communication: Release notes and documentation will be much more explicit about who features are for and which channel they belong to, giving IT admins, developers, and enthusiasts a much more transparent roadmap of what to expect.

From a testing perspective, Microsoft is launching several improvements. First, Beta users get access to features directly. No more waiting or using of third-party tools like ViVeTool to enable them.

Second, users in the experimental channel get options to turn certain features on, if they are not already enabled.

Third, switching between channels should get easier and less cumbersome.

Last but not least, more documentation is always welcome, as Microsoft’s attempts have been lackluster at best until now.

While the announcement may instill hope in Windows testers who have been disappointed by Microsoft so far, it is clear that Microsoft has to deliver. If the company does, it could improve its Windows Insider program significantly in the process.

VeraCrypt is a popular cross-platform encryption software that is available for Windows, Linux and macOS. It is one of the successors of TrueCrypt and can be used to encrypt hard drives, including system drives, and to create data containers on drive that are encrypted.

The developer of the application, Mounir Idrassi, published a project update on Sourceforge a few days ago. There, he explained why the project had been silent for the past few months.

According to his description, Microsoft terminated the account that he used to sign Windows drivers and the bootloader. This affects the Windows version of the encryption software, as updates can’t be signed anymore because of this. The Linux and macOS versions of the software are not affected by this.

To make matters worse, a screenshot with a message by Microsoft suggests that an appeal is not available. It is unclear what that means for the project. While a solution may be found eventually, likely through enough outside pressure to get a Microsoft representative to look at the case, it is certainly problematic when a company that operates its own encryption software — Microsoft with BitLocker — is blocking a competitor from releasing updates for his.

File archives serve plenty of purposes. They compress one or multiple files and folders and make them available as a single file; ideal for distribution and storage.

Many backup tools, for instance, support compressing backups to save storage space.

But how do you ensure that the archives are not corrupt? There are several options, including generating hashes and running verifiers.

However, if you have not created hashes in first place or find this too time consuming or unmanageable, you could test the archives directly using archivers.

PeaZip is an open source archiver for several operating systems. Version 11.0 was released recently and it includes a batch testing option.

Throw any number of support archive formats at the app and it will check each archive. It does so automatically and the only exception to that is when it encounters a password protected archive, as it will prompt for the password in that case.

You get a full list of results in the end that you can go through to find any archives that are damaged.

PeaZip supports all major archive formats. To name a few: ZIP, 7z, BR, TAR, ZipX, RAR, APK, CAB, ISO, and ACE.

Here is how you run the test:

1. Download and install the latest version of the archiver. You can download a portable version or use winget install -e peazip to install it from the command line.
2. Open the application and use the file manager to navigate to the folder with the archives that you want to test.
3. Select them all, for instance by holding down Ctrl and left-clicking on each archive, using Ctrl-A, or right-clicking and picking “select all” from the context menu.
4. Right-click on the selection and select More > Test to start the verification process.

PeaZip tests one archive after another, displaying results in a separate window. You could move all archives into a single folder to make this operation easier, or switch folders to continue testing archives.

All in all, this is a straightforward option to batch test archives on Windows (or any other of the supported operating systems).

If February 2026 was the sprint, March is a marathon of essential infrastructure updates.

Microsoft’s third Patch Tuesday of 2026 has arrived, addressing 84 vulnerabilities in total. While the total count is typical, the release demands close attention: it contains two publicly disclosed zero-day vulnerabilities and eight critical flaws affecting a wide range of enterprise products, including SQL Server, Office, and Azure components.

Here is the breakdown of what you need to know, what to patch first, and what might break.

The March 2026 Patch Day overview

Executive Summary

• Release Date: March 10, 2026
• Total Vulnerabilities: 84
• Critical Vulnerabilities: 8
• Zero-Days (Publicly Disclosed): 2 (SQL Server, .NET)
• Key Action Item: Administrators must prioritize database and application servers due to the SQL Server elevation of privilege flaw and the .NET denial of service vulnerability. Simultaneously, ensure Office updates are deployed to workstations to prevent potential zero-click remote code execution via the Preview Pane.

Important Patches

• CVE-2026-21262 — Microsoft SQL Server Elevation of Privilege Vulnerability
• CVE-2026-26127 — .NET Denial of Service Vulnerability
• CVE-2026-21536 — Microsoft Devices Pricing Program Remote Code Execution Vulnerability
• CVE-2026-26110 — Microsoft Office Remote Code Execution Vulnerability
• CVE-2026-25187 — Windows Winlogon Elevation of Privilege Vulnerability

Cumulative Updates

Deep Dive: The Critical Vulnerabilities

Microsoft confirmed two publicly disclosed zero-day vulnerabilities are fixed this month. Furthermore, Microsoft fixed several critical remote code execution (RCE) and elevation of privilege (EoP) flaws.

Attackers may exploit the issues on systems that have not been patched to bypass protections, elevate privileges, or execute malicious payloads remotely.

Here is the critical overview:

CVE-2026-21262 (Microsoft SQL Server Elevation of Privilege)

This publicly disclosed zero-day allows an authorized attacker to elevate privileges over a network. Due to improper access control, a logged-in user can quietly elevate to become a full database administrator (sysadmin). With that level of control, they can read, modify, or delete data without user interaction.

CVE-2026-26127 (.NET Denial of Service)

The second publicly disclosed zero-day is an out-of-bounds read flaw in the .NET platform (versions 9.0 and 10.0). It allows an unauthenticated remote attacker to crash .NET applications over the network, resulting in a denial of service for any app running on the affected runtime libraries.

CVE-2026-21536 (Microsoft Devices Pricing Program Remote Code Execution)

Scoring a critical 9.8 out of 10 on the CVSS scale, this is the most severe flaw of the month. It allows remote attackers to execute arbitrary code over the network without privileges or user interaction. Notably, this flaw was discovered by an autonomous AI penetration testing agent. Microsoft notes that the vulnerability has been fully mitigated on their end, requiring no direct action from users.

CVE-2026-26110 & CVE-2026-26113 (Microsoft Office Remote Code Execution)

These type confusion and untrusted pointer dereference flaws in Microsoft Office enable remote code execution when malicious files are processed. They are particularly dangerous because they can potentially allow zero-click exploitation if a user simply views a booby-trapped document in the Outlook Preview Pane.

CVE-2026-25187 (Windows Winlogon Elevation of Privilege)

Discovered by Google Project Zero, this vulnerability leverages improper link resolution in the Winlogon process. A locally authenticated attacker with low privileges could exploit a link-following condition to effortlessly escalate to SYSTEM privileges.

Significant Changes in the March 2026 updates

• Sysmon is now built-in: Previously a manual download from Sysinternals, Sysmon is now included as a native component in Windows 11 for better security auditing and monitoring of malicious activity.
• Secure Boot certificate preparation: Windows systems are receiving infrastructure updates to prepare for the upcoming expiration of Secure Boot certificates, which will begin rotating in June 2026.
• Quick Machine Recovery (QMR) expansion: QMR is now turned on automatically on more hardware. This feature allows administrators to revert endpoints to a working state if a disastrous third-party update takes down the system.
• RSAT on Arm64: Remote Server Administration Tools are finally supported on Windows 11 Arm64 devices, allowing administrators to manage Windows Server environments directly from Arm-powered PCs.

First Steps: Your Patch Tuesday Strategy

• Prioritize the zero-days: Map your exposure and prioritize the two zero-day vulnerabilities, focusing heavily on SQL Server environments and .NET application servers.
• Update Office installations: Deploy Microsoft Office updates to all workstations immediately to mitigate the risk of zero-click remote code execution via the Preview Pane.
• Prepare for Secure Boot changes: Ensure your enterprise environment allows the new Secure Boot allowed Key Exchange Key (KEK) updates to install properly to avoid boot issues in the coming months.

Have you ever heard of the Userchoice Protection Driver (UCPD.sys) that Microsoft added to its Windows 10 and Windows 11 operating systems in 2024? It is a protective driver designed to prevent third-party applications or scripts from making changes to Registry keys that fall into the UserChoice category. This includes system defaults, such as the web browser, PDF viewer, or widgets.

Before the introduction, apps or scripts could make changes to default settings on Windows by editing certain keys in the Registry directly. With UCPD active, Microsoft implemented a check that allows or disallows changes to these keys.

If the change comes from a legitimate Microsoft process, it is allowed. If the change comes from a non-Microsoft process,, it is not allowed.

So, using the Settings application works, while using a script to make the changes does not.

While Microsoft has not revealed much about the motivation behind the introduction of the driver, it was at least partially introduced to make hijacking of important user settings difficult.

Granted, this had the added effect that it would be harder for competitors to change the defaults, even when users wanted it to happen.

The Impact

Most users may never notice that Microsoft introduced the feature in the first place. Changing defaults via the Settings app is not prevented and so is not a direct edit to the Registry using the Registry Editor.

However, for system administrators and some advanced users, UCDP has been a major headache as it broke command line tools and scripts.

How to check if the driver is running

Here is one easy method to check if the driver is active on your Windows PC:

1. Open the Start menu.
2. Type cmd and press the Enter-key to load the Command Prompt.
3. Type sc query ucpd.

If you see running next to state, then you have confirmation that the service is active.

Can you do something about it? (Should you?)

The short answer: yes, you can turn this off, but it is not as straightforward as you might want it to be.

Here are the required steps:

• Run sc config UCPD start= disabled from an elevated command prompt window.
• Open Task Scheduler, navigate to \Microsoft\Windows\AppxDeploymentClient, and disable the UCDP velocity task so that it does not turn the driver back on.
• Reboot the system.

I suggest you check whether UCDP is running using the command prompt again to make sure.

Should you disable the feature? My advice: if you did not notice any issues so far, you might not need to disable it. If you have run into problems recently running scripts or apps, then you could consider it, especially if you run them regularly.

Keep in mind though that this is also blocking malicious scripts and apps from making those changes.

Microsoft launched its newest operating system Windows 11 back in October 2021 to mixed reviews. Its predecessor, Windows 10, held the top spot firmly at the time while Windows 7 and Windows 8 were reaching the official end of life dates. While companies could extend support of Windows 7 by three years, Microsoft did not give home users such an option.

Microsoft CEO Satya Nadella announced during the company’s FY26 second-quarter earnings call that Windows 11 has officially surpassed one billion monthly active users.

Windows reached a big milestone: One billion Windows 11 users, up over 45% year-over-year.

In about four years, Windows 11 managed to reached the coveted one billion users mark. Windows 10, which was equally criticized when it launched in 2015, took longer to reach the important milestone.

How much longer? Not that much, it turns out. Let us take a look at the official dates that Microsoft provided for Windows 10 and Windows 11 first.

Windows 10 reached 1 billion monthly active users 1,706 days after it was released by Microsoft. Windows 11 managed to cross the one billion monthly active users mark in 1,576 days.

That is 130 days faster. While not impressively faster, it is important to note that Windows 11 had a handicap all along: new system requirements prevented a sizeable chunk of Windows 10’s userbase from upgrading directly to Windows 11.

While Microsoft never released numbers, estimates suggest that several hundred million devices can’t be upgraded directly. While a high percentage of these devices can be upgraded by skipping the requirements checks, the technical nature of the process likely prevents this on the vast majority of devices running Windows 10.

For users, it does not really matter how fast or slow an operating system growth, provided that it manages to reach a number of users that is sizeable enough to warrant continued support.

Windows 10 Home and Pro editions will reach end of servicing later this year. It will be interesting to see what the millions of home users will do when that time comes.