If your mouse cursor jerks while gaming, suddenly panning the camera uncontrollably, or behaves unnaturally in other ways, the problem may not necessarily be in your mouse hardware. Microsoft recently confirmed a bug in Windows 11 that could affect mouse input in some games, and a fix was released via the October 2026 update (which also fixes dozens of security vulnerabilities, so you might as well install it).

Available as update KB5127648, you can scroll down to the “Gaming” section of the patch notes, where you’ll see Microsoft’s one-line note:

[Gaming] This update fixes an issue that could cause mouse input to stutter in some games.

This fix was not included in the September optional preview update.

The Windows 11 mouse input bug

Microsoft doesn’t provide details as to which specific games were affected, how many users experienced the problem, or what caused the bug. As such, it’s impossible to tell whether all reports of jerky mouse movements were attributable to the same bug. In recent months, many users reported issues after installing Windows updates, and some of those issues persisted even after replacing the mouse or adjusting mouse settings.

One example is a post on the Microsoft Q&A forum from June 2026. In it, a user described problems with camera control in Star Wars: The Old Republic and Final Fantasy XIV. The user tried out various settings for their Logitech G600 mouse, swapped input devices, and performed a clean system restart. According to their account, the problem persisted. There have been similar complaints in the past as well. For instance, in February 2025, other users on the Microsoft Q&A forum reported persistently laggy and jerky mouse movements on Windows 11 24H2.

Current discussions on Reddit also show similar reports, with gamers reporting jerky camera movements in The Division 2, even though the game itself runs smoothly. In posts here and here, they discuss possible causes like mouse polling rate, drivers, and other hardware components.

It hasn’t been confirmed whether these specific cases are linked to the Windows bug that has now been fixed. However, the entry in Microsoft’s release notes shows that at least one such issue was indeed caused by the operating system itself, not mouse hardware.

How to install the fix

The fix is included in security update KB5127648 dated October 13th, 2026. It’s available for Windows 11 24H2, 25H2, and 26H2. To install the update, follow these steps:

1. Open the Windows 11 Settings.
2. Go to Windows Update.
3. Click Check for updates.
4. Download and install the KB5127648 update if it’s available.
5. Restart your PC.

This update brings Windows 11 26H2 to Build 26300.9711, 25H2 to Build 26200.9711, and 24H2 to Build 26100.9711. If Windows Update does not offer the package, or the installation fails, you can also grab for it via the Microsoft Update Catalog.

If you’re experiencing problems with jerky mouse input while gaming, you should first check whether the update has already been installed.

What if your mouse continues to stutter?

Even after installing the update, problems with mouse input may still occur. Other possible causes can include out-of-date mouse, USB, or graphics card drivers; very high polling rates; radio interference with wireless mice; and issues with Nvidia G-Sync or Adaptive Sync affecting the display.

Another potential source of problems is USB docks and connected monitors. As early as 2025, a user on the Microsoft Q&A forum described how their mouse worked without any issues on a Dell laptop normally, but became jerky when connected to external monitors via a Kensington dock.

If the October update doesn’t resolve the issue, it’s therefore advisable to connect the mouse directly to the PC, try different USB ports, and check the drivers. For wireless models, you can also try switching the wireless connection or reducing the polling rate.

In an age of 4TB SSDs and massive NVMe drives, many users tend to leave the entire storage space as a single, huge system drive. While this is convenient, from an administrative point of view it is a risky move that amounts to flying blind. Instead, we recommend strategically partitioning your largest drives.

This brings tangible benefits for data security, system recovery, and backup efficiency. Think of partitions as digital firewalls within your hardware. If your operating system becomes corrupted by a faulty driver, a failed update, or even malware, a clean reinstallation is often the quickest way back to a stable system.

However, if you’ve stored everything on a single partition, you’ll have to laboriously back up terabytes of data before reinstalling, or risk losing it when formatting the drive.

By separating the operating system onto partition C: and your user data onto partition D:, you can completely wipe and reinstall Windows, while your game collections, video projects, and documents on the second partition remain completely untouched. This not only saves time but also spares you a lot of stress in crisis situations.

To implement this optimization, you must first analyze your current configuration. To do this, open the Command Prompt with administrator rights and enter the command fsutil fsinfo ntfsinfo C:, then press the Enter key to confirm. Look for the value ‘Bytes per cluster’ in the results.

By default, Windows uses 4KB, which is ideal for the system partition to minimize fragmentation when dealing with many small system files. However, for data-only partitions where you mainly store large files such as 4K videos or backups, it makes sense to adjust the cluster size to 64KB.

Here’s how to do it: The neatest way to change the cluster size in Windows 11 is via Windows Settings. Press the Windows + I key combination to open Settings. In the left-hand menu, navigate to ‘System’ and then click on ‘Storage’ on the right. Scroll down to the ‘Storage management’ section.

Next, expand ‘Advanced storage settings’ and select ‘Disks and volumes.’ A list of all physical drives will appear. Click the arrow next to your hard drive to view the associated partitions (volumes). Select the desired data partition and click the ‘Properties’ button.

Next, click the ‘Format’ button. The crucial dialog box will now open. Here, under ‘Label,’ enter a name for your drive. Ensure that ‘NTFS’ is selected under ‘File system.’ In the ‘Allocation unit size’ drop-down menu, select ‘64KB’ explicitly instead of ‘Standard (4KB).’

Tick the box next to ‘Perform quick format’ and confirm the process by clicking ‘Format.’ Please note: This process will irrevocably delete all data on this partition. You should therefore only carry it out on newly created or empty data partitions.

This adjustment to 64KB is so effective because it reduces fragmentation in large files and minimizes the amount of metadata that needs to be managed in the Master File Table (MFT). Please bear in mind a technical limitation: With the standard cluster size of 4KB, an NTFS partition is limited to a maximum of 16TB.

If you upgrade to even larger drives in future, you must use larger clusters to be able to utilize the full capacity. On modern SSDs, you should also ensure that the partitions are aligned with the internal NAND memory.

Nowadays, Windows handles this correctly and automatically when creating partitions via Disk Management or the Settings app, in order to avoid unnecessary write cycles (write amplification).

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Yesterday was October Patch Tuesday, and Microsoft’s security updates addressed 1,416 new vulnerabilities. Not only is that another record broken, but it’s also the first time over 1,000 flaws were fixed in a single month. Indeed, October 2026 saw more security vulnerabilities fixed in the month than were fixed in any previous year.

Alongside flaws fixed in Windows and Office, we also saw a bunch of fixes in Exchange Server, SQL Server, Hyper-V, Skype for Business, Microsft Defender, .NET Framework, Visual Studio, and Microsoft’s cloud services.

Microsoft classifies 85 of the 1,416 vulnerabilities as “critical,” including 67 remote code execution (RCE) vulnerabilities. The other vulnerabilities are classified as “high risk,” with one vulnerability already being exploited in the wild while two were publicly known in advance.

The next Patch Tuesday is scheduled for November 10th, 2026.

Windows security vulnerabilities

A large number of the vulnerabilities—over 1,000 this time—are spread across the various Windows versions (10, 11, Server) for which Microsoft still provides security updates, including Windows 10 via the Extended Security Updates program, which was extended until October 12th, 2027.

Note: If you’re still on Windows 11 24H2, this is your last Patch Tuesday. Computers running 24H2 will no longer receive security updates going forward. When prompted by Windows Update, you should upgrade to Windows 11 25H2 or 26H2. That’ll keep you secure and up to date.

Windows under attack

One Windows security vulnerability is already being exploited in the wild this month. CVE-2026-96951 in the Windows Shell allows attackers to bypass the system’s defenses by disguising the origin of an executable file from the internet (Mark of the Web, or MotW).

Critical Windows vulnerabilities

Microsoft has classified 42 Windows vulnerabilities as critical, including 30 RCE vulnerabilities. Via these flaws, an attacker could remotely execute injected code without authentication or user interaction. The malicious code could then spread further across the network.

Microsoft Edge security vulnerabilities

The latest security update to Microsoft Edge 155.0.4283.45 is dated October 8th and based on Chromium 155.0.8059.40. It addresses 247 Chromium vulnerabilities, which are not included in the sum of flaws fixed in Microsoft Edge this month.

Microsoft Office security vulnerabilities

Microsoft has fixed 194 vulnerabilities in its various Office products, including 25 RCE vulnerabilities classified as critical. With “critical” RCE vulnerabilities in Office, the preview pane is usually an attack vector—a user doesn’t need to open an infected file for an attack to succeed, but rather only needs to preview it in the preview pane. Meanwhile, “high risk” RCE vulnerabilities usually require a user to open an infected Office file in a vulnerable Office product (open-and-own).

Among the numerous vulnerabilities in SharePoint, CVE-2026-102866 is an elevation of privilege (EoP) vulnerability that Microsoft classifies as critical. It is also the only SharePoint vulnerability that an attacker could exploit without a user login. They would need to obtain a valid user token, modify it, and impersonate that user on the server.

Exchange Server security vulnerabilities

Microsoft has fixed 7 vulnerabilities in Exchange Server this month. Six of these are classified as high risk, including five EoP vulnerabilities. CVE-2026-70571 is also included, an RCE vulnerability classified as critical.