Microsoft Windows 11 Version 23H2 vulnerabilities

CVE-2026-21239 [HIGH] CWE-122 CVE-2026-21239: Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges loc Heap-based buffer overflow in Windows Kernel allows an authorized attacker to elevate privileges locally.

CVE-2026-21248 [HIGH] CWE-122 CVE-2026-21248: Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally. Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.

CVE-2026-21244 [HIGH] CWE-122 CVE-2026-21244: Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally. Heap-based buffer overflow in Windows Hyper-V allows an authorized attacker to execute code locally.

CVE-2026-21513 [HIGH] CWE-693 CVE-2026-21513: Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a securit Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.

CVE-2026-21519 [HIGH] CWE-843 CVE-2026-21519: Access of resource using incompatible type ('type confusion') in Desktop Window Manager allows an au Access of resource using incompatible type ('type confusion') in Desktop Window Manager allows an authorized attacker to elevate privileges locally.

CVE-2026-21508 [HIGH] CWE-287 CVE-2026-21508: Improper authentication in Windows Storage allows an authorized attacker to elevate privileges local Improper authentication in Windows Storage allows an authorized attacker to elevate privileges locally.

CVE-2026-21253 [HIGH] CWE-416 CVE-2026-21253: Use after free in Mailslot File System allows an authorized attacker to elevate privileges locally. Use after free in Mailslot File System allows an authorized attacker to elevate privileges locally.

CVE-2026-21236 [HIGH] CWE-122 CVE-2026-21236: Heap-based buffer overflow in Windows Ancillary Function Driver for WinSock allows an authorized att Heap-based buffer overflow in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

CVE-2026-21231 [HIGH] CWE-362 CVE-2026-21231: Concurrent execution using shared resource with improper synchronization ('race condition') in Windo Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Kernel allows an authorized attacker to elevate privileges locally.

CVE-2026-21242 [HIGH] CWE-416 CVE-2026-21242: Use after free in Windows Subsystem for Linux allows an authorized attacker to elevate privileges lo Use after free in Windows Subsystem for Linux allows an authorized attacker to elevate privileges locally.

CVE-2026-21255 [HIGH] CWE-284 CVE-2026-21255: Improper access control in Windows Hyper-V allows an authorized attacker to bypass a security featur Improper access control in Windows Hyper-V allows an authorized attacker to bypass a security feature locally.

CVE-2026-21238 [HIGH] CWE-284 CVE-2026-21238: Improper access control in Windows Ancillary Function Driver for WinSock allows an authorized attack Improper access control in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

CVE-2026-21246 [HIGH] CWE-122 CVE-2026-21246: Heap-based buffer overflow in Microsoft Graphics Component allows an authorized attacker to elevate Heap-based buffer overflow in Microsoft Graphics Component allows an authorized attacker to elevate privileges locally.

CVE-2026-21247 [HIGH] CWE-20 CVE-2026-21247: Improper input validation in Windows Hyper-V allows an authorized attacker to execute code locally. Improper input validation in Windows Hyper-V allows an authorized attacker to execute code locally.

CVE-2026-21533 [HIGH] CWE-269 CVE-2026-21533: Improper privilege management in Windows Remote Desktop allows an authorized attacker to elevate pri Improper privilege management in Windows Remote Desktop allows an authorized attacker to elevate privileges locally.

CVE-2026-21234 [HIGH] CWE-362 CVE-2026-21234: Concurrent execution using shared resource with improper synchronization ('race condition') in Windo Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Connected Devices Platform Service allows an authorized attacker to elevate privileges locally.

CVE-2026-21235 [HIGH] CWE-416 CVE-2026-21235: Use after free in Microsoft Graphics Component allows an authorized attacker to elevate privileges l Use after free in Microsoft Graphics Component allows an authorized attacker to elevate privileges locally.

CVE-2026-21222 [MEDIUM] CWE-532 CVE-2026-21222: Insertion of sensitive information into log file in Windows Kernel allows an authorized attacker to Insertion of sensitive information into log file in Windows Kernel allows an authorized attacker to disclose information locally.

CVE-2026-21525 [MEDIUM] CWE-476 CVE-2026-21525: Null pointer dereference in Windows Remote Access Connection Manager allows an unauthorized attacker Null pointer dereference in Windows Remote Access Connection Manager allows an unauthorized attacker to deny service locally.

CVE-2026-21249 [LOW] CWE-73 CVE-2026-21249: External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spo External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing locally.