Microsoft Ships KB5083769 for Windows 11 25H2, Patching Kernel, WebView2 and Print Spooler Flaws

KB5083769 is a critical cumulative security update for Windows 11 version 25H2, released on April 14, 2026. The documentation states it also applies to version 24H2 and addresses multiple vulnerabilities that could let attackers execute arbitrary code, escalate privileges or bypass security features.

After installation, systems report operating-system build 26200.8246 on version 25H2 and 26100.8246 on version 24H2. The update is cumulative, so it also includes prior fixes for the affected branches.

According to the update documentation, KB5083769 resolves six tracked vulnerabilities across core Windows components:

• CVE-2026-20001 and CVE-2026-20002 — Windows Kernel privilege escalation via buffer overflow conditions in kernel-mode drivers (ntoskrnl.exe and related modules), potentially reaching SYSTEM-level access.
• CVE-2026-20003 — Microsoft Edge WebView2 remote code execution through specially crafted web content in applications embedding WebView2 controls.
• CVE-2026-20004 — Windows Graphics Component memory corruption affecting win32k.sys and DirectX components, potentially leading to arbitrary code execution.
• CVE-2026-20005 — Windows Common Log File System (CLFS) security feature bypass affecting the clfs.sys driver.
• CVE-2026-20006 — Windows Print Spooler elevation of privilege affecting the spoolsv.exe service.

The documentation attributes the underlying issues to improper input validation and memory management, including insufficient bounds checking in kernel-mode drivers and inadequate validation of user-supplied graphics data.

The update applies to the following editions and architectures:

• Windows 11 version 25H2 on x64 systems — build 26200.8246
• Windows 11 version 25H2 on ARM64 systems — build 26200.8246
• Windows 11 version 24H2 on x64 systems — build 26100.8246
• Windows 11 version 24H2 on ARM64 systems — build 26100.8246

The update is distributed through Windows Update, the Microsoft Update Catalog (for offline installation), WSUS, Microsoft System Center Configuration Manager and Microsoft Intune. It is classified as a critical security update with automatic approval recommended for enterprise environments. A restart is required to complete installation.

Per the documentation, the package is approximately 890 MB for x64 systems and 720 MB for ARM64 systems, and systems need at least 2 GB of available disk space.

Verify installation with PowerShell

Get-HotFix -Id KB5083769

Get-WmiObject -Class Win32_QuickFixEngineering | Where-Object {$_.HotFixID -eq "KB5083769"}

Get-ComputerInfo | Select-Object WindowsVersion, WindowsBuildLabEx

The documentation lists several known issues administrators should account for during rollout:

• Installation may fail with error 0x80070070 on systems with less than 2 GB of free disk space; free up space before retrying.
• Temporary system slowdown can occur during installation, particularly on devices with traditional hard drives, and resolves after completion.
• Some third-party antivirus products may need updates to remain compatible; check with the vendor if issues occur.

Unpatched Windows 11 25H2 and 24H2 systems remain exposed to privilege-escalation, remote-code-execution and security-bypass vulnerabilities across core OS components.

Security: Successful exploitation could grant SYSTEM-level access, execute arbitrary code or bypass security controls.

Microsoft's KB5083769, released April 14, 2026, patches six vulnerabilities in Windows 11 25H2 and 24H2 and updates systems to build 26200.8246 / 26100.8246.