KB5094126: Windows 11’s June 2026 Patch Tuesday — Shared Audio, CPU Boost, 200 Security Fixes, and Three Nasty Bugs

Microsoft released KB5094126 on June 9, 2026 — the June Patch Tuesday mandatory cumulative security update for Windows 11 versions 25H2 and 24H2. It moves systems to OS builds 26200.8655 and 26100.8655.

This is not a routine maintenance release. Independent testing described KB5094126 as “the most feature-packed monthly update Windows 11 has seen in a long time” — bringing Shared Audio over Bluetooth, a CPU low-latency performance profile, simultaneous camera access for multiple apps, and the first wave of K2 platform improvements. It also fixed 200 vulnerabilities across Microsoft products and patched three zero-days.

But it also shipped with three confirmed bugs — a Recycle Bin filename issue that made permanent deletion confusing, a broken OLE automation that stopped third-party apps from opening Office, and BSODs on some business PCs. All three required separate fixes.

Here is everything in one place.

What Is KB5094126?

KB5094126 is a cumulative security update for Windows 11 versions 25H2 and 24H2, released on June 9, 2026. It includes the latest security fixes and quality improvements, along with non-security updates from the previous month’s optional preview release.

It is mandatory — it installs automatically through Windows Update unless you have updates paused. You will see it in Windows Update as “2026-06 Security Update (KB5094126) (26200.8655)” on Windows 11 25H2 systems.

The June 2026 Patch Tuesday is particularly heavy, with a total of 200 vulnerabilities fixed across Microsoft products. It also patches 3 zero-day flaws, including the GreenPlasma and YellowKey flaws — the YellowKey flaw being a BitLocker bypass vulnerability.

The same update applies to both Windows 11 25H2 and 24H2 — there are no exclusive changes between the two versions in this release.

For Windows 11 23H2 users, the equivalent June 2026 update is KB5093998, not KB5094126.

The 200 Vulnerabilities and Three Zero-Days

The security content in KB5094126 is substantial. 200 vulnerabilities fixed across Microsoft products in a single month is a high number — comparable to the scale of the July 2026 KB5101650 which fixed 570 vulnerabilities.

The three zero-day patches are the priority items:

GreenPlasma — A zero-day vulnerability that was being actively exploited before Microsoft’s patch was ready. The specific component affected has not been fully detailed in public documentation, but it is classified as a remote code execution or privilege escalation vulnerability.

YellowKey — BitLocker Bypass — This is the more alarming of the three zero-days. A BitLocker bypass vulnerability allows an attacker with physical access to a device — or in certain remote scenarios — to circumvent BitLocker drive encryption. For enterprise environments where BitLocker is the primary data-at-rest protection mechanism, this is a high-priority patch.

The third zero-day has been patched without a public codename in Microsoft’s documentation.

If you have not installed KB5094126 and are running Windows 11 25H2 or 24H2, the BitLocker bypass vulnerability — YellowKey — is the most urgent reason to install it.

Every New Feature in KB5094126

Shared Audio

One of the most interesting additions in this release is Shared Audio, a new feature powered by Bluetooth LE Audio technology. The feature allows two people to listen to audio from the same Windows 11 PC simultaneously using compatible Bluetooth earbuds or headphones.

This is a genuinely new capability that was not possible in Windows before KB5094126. Bluetooth LE Audio — the newer Bluetooth audio standard — supports multiple simultaneous audio streams to different devices. Shared Audio uses this capability to let two pairs of wireless earbuds or headphones connect to the same PC and receive the same audio at the same time.

Practical applications are immediate: two people watching a video on a laptop on a plane, a parent and child listening to the same content, or two collaborators listening to the same audio recording simultaneously during review. The key requirement is that both sets of headphones must support Bluetooth LE Audio — legacy Bluetooth audio devices are not compatible.

Low Latency Performance Profile — CPU Boost for Games

KB5094126 introduces a new CPU performance mode called Low Latency Profile, which Microsoft’s testing showed improves frame rate performance in games and latency-sensitive applications.

The Low Latency Profile adjusts how Windows schedules CPU resources — prioritizing low-latency task completion over maximum throughput efficiency. For gaming, this means the CPU responds to input and rendering requests faster, reducing the perception of input lag and improving frame consistency.

This feature enables itself automatically when the system detects a supported workload. It does not require manual configuration.

Multi-App Camera Access

Windows 11 previously limited camera access to one application at a time. If one application was using your webcam, any other application trying to access the camera received an error.

KB5094126 removes this restriction. Two apps can now access the same camera stream simultaneously — meaning you can run a video call and a recording application at the same time, or use both a meeting platform and a dedicated camera control application without one blocking the other.

Windows Search Improvements

The Windows Search experience receives improvements in KB5094126 that produce more relevant results for natural language queries and reduce the time between typing and seeing results. The changes also improve search across networked drives and shared folders.

NPU Monitoring in Task Manager

For Copilot+ PCs with dedicated Neural Processing Units, Task Manager now includes NPU monitoring in its Performance tab. Users can see real-time NPU usage, temperature, and load alongside CPU, GPU, and memory metrics. This makes it easier to understand when AI processing tasks are utilizing the NPU versus falling back to CPU or GPU.

Windows Hello Optimizations

Windows Hello facial recognition receives performance improvements in KB5094126 that reduce authentication time and improve recognition accuracy in varied lighting conditions. The changes are most noticeable on systems where face authentication previously took more than two seconds.

First K2 Platform Improvements

This is the first K2 program update from Microsoft, which makes it an important release. Microsoft is planning a series of updates to improve Windows 11 stability and performance — this one contains the first wave of enhancements.

Windows K2 is Microsoft’s internal program for next-generation Windows platform improvements — a series of updates that collectively move Windows 11 toward improved performance, stability, and hardware integration. KB5094126 delivers the first publicly available K2 improvements, though the specific technical changes are bundled within the larger update package.

Custom User Folder Name at Setup

A small but practical quality-of-life improvement: during Windows 11 setup, you can now choose a custom name for your user folder at the step where you define the machine name. Previously, the user folder name was automatically derived from your account name with no option to change it during initial setup.

Secure Boot Certificate Continued Rollout

With this update, Windows quality updates include additional high-confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates.

The Secure Boot certificate renewal that began in earlier 2026 updates continues with KB5094126. Devices that demonstrate sufficient successful update history receive the new certificates automatically. Devices that have not yet received the certificates continue to function normally while the phased rollout completes.

Virtualization Stop Error Fix

Microsoft has resolved an issue affecting some devices after previous updates that could trigger HYPERVISOR_ERROR (0x20001) and KMODE_EXCEPTION_NOT_HANDLED (0x1E) errors. These errors could appear during system restart, while running virtual machines, or when using certain games.

This fix specifically addresses systems that experienced stop errors after installing the May 2026 update KB5089573. Enterprise environments running Hyper-V workloads and gamers who encountered unexpected crashes should see stability improvements after KB5094126.

Folder Customization Security Hardening

This update introduces a security hardening change to how Windows processes desktop.ini files. As a result, some users might notice missing custom folder icons or localized folder names for content from downloaded or remote locations. Note that access to folders is not affected.

This is a security improvement that has a visible side effect. The desktop.ini file is a hidden configuration file inside Windows folders that stores custom folder settings — icons, localized names, and other attributes. A security vulnerability in how Windows processed these files from untrusted locations — downloaded content and network locations — prompted a hardening change.

The side effect: custom folder icons and localized folder names for folders from those locations may not appear after KB5094126. The folders themselves are completely accessible — only the visual customization is affected.

DISM Fix

KB5094126 fixes an issue that caused the DISM tool to fail with error 0x800f0915 when running the /RestoreHealth command on some Windows 11 24H2 devices. If you previously found that running DISM for system repairs failed with this specific error, KB5094126 resolves the underlying cause.

Full Feature Summary Table

Feature	Type	Details
Shared Audio	New	Two Bluetooth LE Audio devices receive the same audio simultaneously
Low Latency CPU Profile	New	Improves game performance and input responsiveness
Multi-App Camera Access	New	Two apps can use the same camera at once
Windows Search	Improved	Faster, more relevant results
NPU Monitoring	New	Task Manager shows NPU usage on Copilot+ PCs
Windows Hello	Improved	Faster, more accurate facial recognition
K2 Platform Wave 1	New	First K2 stability and performance improvements
Custom User Folder Name	New	Set during Windows setup
Secure Boot certificates	Ongoing	Expanded phased rollout
Hyper-V/VM stability	Fixed	Stop errors after KB5089573 resolved
Folder customization hardening	Changed	Custom icons may not show from remote/downloaded folders
DISM /RestoreHealth	Fixed	Error 0x800f0915 on 24H2 devices fixed

Three Known Issues — The Bugs That Shipped With KB5094126

KB5094126 launched with three confirmed problems. Understanding each helps you decide whether to install, how to work around them, and which subsequent update fixed each.

Bug 1 — Recycle Bin Shows Internal Filename

Windows 11 KB5094126 broke the Recycle Bin’s ability to correctly display the file name, so it shows the internal name instead of the original file name. So instead of asking whether you want to permanently delete Report.docx, Windows might show something like $R4ABC12.docx.

When permanently deleting a file from the Recycle Bin — pressing Shift+Delete or choosing “Delete permanently” — the confirmation dialog showed the internal Recycle Bin filename ($R4ABC12.docx format) rather than the original file name (Report.docx). This made it genuinely unclear which file was being permanently deleted, creating risk of accidentally deleting something you intended to restore.

Workaround: Before permanently deleting, check the original file name by right-clicking the file in the Recycle Bin and selecting Properties — the original location and name appear there.

Fixed in: KB5095093 — the June 23 optional preview update — and subsequently in KB5101650 for all users.

Bug 2 — Office Apps Won’t Open From Third-Party Applications

Microsoft quietly confirmed that Windows 11 KB5094126 accidentally broke OLE automation, which is used by third-party apps to integrate Office apps. It allows one app to control another. For example, third-party apps may fail to open Office apps such as Word, PowerPoint, or Excel after the June 2026 update is installed.

OLE automation is the Windows mechanism that allows applications to control other applications. A CRM that opens a Word document when you click “Generate Letter,” an accounting application that exports directly to Excel, or a project management tool that creates a PowerPoint presentation — all of these depend on OLE automation.

KB5094126 broke this mechanism. Any third-party application that attempts to launch or control Office applications through OLE automation received an error.

Workaround: Open Office applications directly, then access content from within the Office app rather than launching Office from the third-party application.

Fixed in: KB5095093 — the June 23 optional preview — and subsequently in KB5101650.

Bug 3 — BSODs on Business PCs

Multiple reports emerged from enterprise environments of Blue Screen of Death errors on business PCs after installing KB5094126. The BSODs appeared with various stop codes and did not affect all hardware configurations, making the issue difficult to predict or reproduce systematically.

Microsoft acknowledged the issue was under investigation but did not provide a specific root cause analysis in public documentation.

Workaround: If your organization’s PCs are experiencing BSODs after KB5094126, uninstalling the update and waiting for KB5101650 is the practical path. KB5101650 includes a revised version of the changes in KB5094126 that addresses the stability issues.

Status: Addressed in KB5101650.

Should You Install KB5094126 Now?

Since we are now in July 2026, the question of whether to install KB5094126 separately is primarily relevant to devices that have not received any updates since before June 9.

If you have KB5101650 installed: You already have all of KB5094126’s security content plus July’s patches. The bugs that shipped with KB5094126 are fixed in KB5101650. You do not need KB5094126 separately.

If your device has not received any June or July updates: Install KB5043080 first as a prerequisite, then check Windows Update for the most current available update — which will be KB5101650, incorporating all of KB5094126’s content with the bugs already fixed.

If you need KB5094126 specifically for offline deployment or testing: The update is available from the Microsoft Update Catalog. Be aware of the three known bugs and plan for KB5095093 or KB5101650 to follow.

How to Install KB5094126

Method 1 — Windows Update

Go to Settings, Windows Update, Check for updates. KB5094126 will appear if your system needs it and has not already advanced past this build. Click Download and install. Restart when prompted.

Method 2 — Microsoft Update Catalog

Go to catalog.update.microsoft.com. Search for KB5094126. Select the package for Windows 11 25H2 or 24H2 matching your architecture. Download and run the .MSU file. Restart when complete.

If you encounter error 0x80244022 during download, check our Windows Update error 0x80244022 fix guide. If installation fails due to a missing prerequisite, install KB5043080 first.

Frequently Asked Questions