Windows 11 23h2 vulnerabilities

301 known vulnerabilities in Windows 11 23h2 from Microsoft. 291 are rated high or critical, and 64 have been exploited in real attacks. Each entry lists the affected versions and the release that fixes it, where the vendor has published one.

Latest first

• 7.0 High severity

  Windows 10 Version 21H2: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-59126Aug 11, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Event Logging Service allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-59122Aug 11, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Telephony Service allows an authorized attacker to elevate privileges locally.

• 8.8 High severity

  Windows 10 Version 1607: Improper Neutralization of Special Elements used in a Command

  CVE-2026-49179Aug 11, 2026Microsoft

  Improper neutralization of special elements used in a command ('command injection') in Windows Active Directory allows an unauthorized attacker to execute code over a network.

• 7.0 High severity

  Windows 11 version 23H2: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-48572Jul 14, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows App Installer allows an authorized attacker to elevate privileges locally.

• 7.8 High severity

  Windows 11 version 23H2: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-44800Jul 14, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications allows an authorized attacker to elevate privileges locally.

• 7.5 High severity

  Windows 10 Version 1607: Memory Allocation with Excessive Size Value

  CVE-2026-40378Jul 14, 2026MicrosoftEPSS 1.17%

  Memory allocation with excessive size value in Windows Local Security Authority Subsystem Service (LSASS) allows an unauthorized attacker to deny service over a network.

• 8.1 High severity

  Windows 10 Version 1607: Use After Free

  CVE-2026-45635Jun 9, 2026Microsoft

  Access of resource using incompatible type ('type confusion') in Universal Plug and Play (upnp.dll) allows an unauthorized attacker to execute code over a network.

• 7.0 High severity

  Windows 10 Version 1607: Use After Free

  CVE-2026-45603Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-45601Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-45598Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 11 version 23H2: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-45597Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in UI Automation Manager (uiamanager.dll) allows an authorized attacker to elevate privileges locally.

• 7.8 High severity

  Windows 10 Version 1607: Improper Link Resolution Before File Access

  CVE-2026-45586Jun 9, 2026MicrosoftEPSS 3.63%

  Improper link resolution before file access ('link following') in Windows Collaborative Translation Framework allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 10 Version 21H2: Time-of-check Time-of-use (TOCTOU) Race Condition

  CVE-2026-45487Jun 9, 2026Microsoft

  Time-of-check time-of-use (TOCTOU) race condition in Program Compatibility Assistant Service allows an authorized attacker to elevate privileges locally.

• 7.8 High severity

  Windows 10 Version 1809: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-42991Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications allows an authorized attacker to elevate privileges locally.

• 7.8 High severity

  Windows 10 Version 1809: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-42979Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications allows an authorized attacker to elevate privileges locally.

• 7.8 High severity

  Windows 10 Version 1809: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-42978Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications allows an authorized attacker to elevate privileges locally.

• 7.8 High severity

  Windows 10 Version 1809: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-42977Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications allows an authorized attacker to elevate privileges locally.

• 7.5 High severity

  Remote Desktop client for Windows Desktop: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-42913Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Remote Desktop Client allows an unauthorized attacker to execute code over a network.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-42912Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Telephony Service allows an authorized attacker to elevate privileges locally.

• 7.5 High severity

  Remote Desktop client for Windows Desktop: Out-of-bounds Write

  CVE-2026-42909Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Remote Desktop Client allows an unauthorized attacker to execute code over a network.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-42836Jun 9, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Function Discovery Service (fdwsd.dll) allows an authorized attacker to elevate privileges locally.

• 7.8 High severity

  Windows 10 Version 21H2: External Control of File Name or Path

  CVE-2026-41088May 12, 2026Microsoft

  Access of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

• 7.8 High severity

  Windows 10 Version 1607: Stack-based Buffer Overflow

  CVE-2026-40399May 12, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows TCP/IP allows an authorized attacker to elevate privileges locally.

• 7.5 High severity

  Windows 10 Version 1607: Missing Release of Memory after Effective Lifetime

  CVE-2026-35424May 12, 2026MicrosoftEPSS 1.19%

  Missing release of memory after effective lifetime in Windows Internet Key Exchange (IKE) Protocol allows an unauthorized attacker to deny service over a network.

• 7.0 High severity

  Windows 10 Version 1607: Use After Free

  CVE-2026-35416May 12, 2026MicrosoftEPSS 1.65%

  Access of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-34351May 12, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows TCP/IP allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-34345May 12, 2026Microsoft

  Access of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

• 7.8 High severity

  Windows 10 Version 1607: Access of Resource Using Incompatible Type

  CVE-2026-34344May 12, 2026Microsoft

  Access of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-34342May 12, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Print Spooler Components allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-34334May 12, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows TCP/IP allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-34331May 12, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Win32K - GRFX allows an authorized attacker to elevate privileges locally.

• 7.8 High severity

  Windows 10 Version 1607: Integer Overflow or Wraparound

  CVE-2026-34330May 12, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Win32K - GRFX allows an authorized attacker to elevate privileges locally.

• 7.0 High severity

  Windows 10 Version 1809: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-33839May 12, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Win32K - GRFX allows an authorized attacker to elevate privileges locally.

• 7.5 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-32161May 12, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Native WiFi Miniport Driver allows an unauthorized attacker to execute code over an adjacent network.

• 8.1 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-33827Apr 14, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows TCP/IP allows an unauthorized attacker to execute code over a network.

• 9.8 Critical severity

  Microsoft Internet Key Exchange (IKE) Service Extensions Double Free Exploited

  CVE-2026-33824Apr 14, 2026MicrosoftEPSS 77.4%

  Double free in Windows IKE Extension allows an unauthorized attacker to execute code over a network.

• 7.0 High severity

  Windows 10 Version 1607: Concurrent Execution using Shared Resource with Improper Synchronization

  CVE-2026-33104Apr 14, 2026Microsoft

  Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Win32K - GRFX allows an authorized attacker to elevate privileges locally.

• 8.8 High severity

  Windows 10 Version 1607: Protection Mechanism Failure

  CVE-2026-32225Apr 14, 2026MicrosoftEPSS 1.24%

  Improper neutralization of special elements used in a command ('command injection') in Windows Shell allows an unauthorized attacker to bypass a security feature over a network.

• 4.3 Medium severity

  Microsoft Windows Protection Mechanism Failure Exploited

  CVE-2026-32202Apr 14, 2026MicrosoftEPSS 71.3%

  Protection mechanism failure in Windows Shell allows an unauthorized attacker to perform spoofing over a network.

• 7.8 High severity

  Windows 10 Version 1607: Improper Neutralization of Special Elements used in a Command

  CVE-2026-32183Apr 14, 2026Microsoft

  Improper neutralization of special elements used in a command ('command injection') in Windows Snipping Tool allows an unauthorized attacker to execute code locally.