Microsoft Windows 11 Version 26H1 vulnerabilities

CVE-2026-50424 [HIGH] CWE-822 CVE-2026-50424: Untrusted pointer dereference in Windows Domain Controller allows an unauthorized attacker to deny s Untrusted pointer dereference in Windows Domain Controller allows an unauthorized attacker to deny service over a network.

CVE-2026-50667 [HIGH] CWE-362 CVE-2026-50667: Concurrent execution using shared resource with improper synchronization ('race condition') in Windo Concurrent execution using shared resource with improper synchronization ('race condition') in Windows NTFS 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-2026-49805 [HIGH] CWE-284 CVE-2026-49805: Improper access control in Windows Win32K allows an authorized attacker to elevate privileges locall Improper access control in Windows Win32K allows an authorized attacker to elevate privileges locally.

CVE-2026-48575 [HIGH] CWE-693 CVE-2026-48575: Protection mechanism failure in Windows Secure Boot allows an authorized attacker to bypass a securi Protection mechanism failure in Windows Secure Boot allows an authorized attacker to bypass a security feature locally.

CVE-2026-48570 [HIGH] CWE-693 CVE-2026-48570: Protection mechanism failure in Windows Secure Boot allows an authorized attacker to bypass a securi Protection mechanism failure in Windows Secure Boot allows an authorized attacker to bypass a security feature locally.

CVE-2026-48568 [HIGH] CWE-693 CVE-2026-48568: Protection mechanism failure in Windows Secure Boot allows an authorized attacker to bypass a securi Protection mechanism failure in Windows Secure Boot allows an authorized attacker to bypass a security feature locally.

CVE-2026-45588 [HIGH] CWE-693 CVE-2026-45588: Protection mechanism failure in Windows Secure Boot allows an authorized attacker to bypass a securi Protection mechanism failure in Windows Secure Boot allows an authorized attacker to bypass a security feature locally.

CVE-2026-48578 [HIGH] CWE-284 CVE-2026-48578: Improper access control in Windows Secure Boot allows an authorized attacker to elevate privileges l Improper access control in Windows Secure Boot allows an authorized attacker to elevate privileges locally.

CVE-2026-21241 [HIGH] CWE-416 CVE-2026-21241: Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to ele Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

CVE-2026-50388 [HIGH] CWE-125 CVE-2026-50388: Out-of-bounds read in Windows NTFS allows an unauthorized attacker to execute code locally. Out-of-bounds read in Windows NTFS allows an unauthorized attacker to execute code locally.

CVE-2026-50308 [HIGH] CWE-122 CVE-2026-50308: Integer underflow (wrap or wraparound) in Windows NTFS allows an unauthorized attacker to execute co Integer underflow (wrap or wraparound) in Windows NTFS allows an unauthorized attacker to execute code locally.

CVE-2026-58609 [HIGH] CWE-125 CVE-2026-58609: Out-of-bounds read in Microsoft Graphics Component allows an unauthorized attacker to execute code l Out-of-bounds read in Microsoft Graphics Component allows an unauthorized attacker to execute code locally.

CVE-2026-26161 [HIGH] CWE-20 CVE-2026-26161: Untrusted pointer dereference in Windows Sensor Data Service allows an authorized attacker to elevat Untrusted pointer dereference in Windows Sensor Data Service allows an authorized attacker to elevate privileges locally.

CVE-2026-50673 [HIGH] CWE-367 CVE-2026-50673: Null pointer dereference in Windows Kernel allows an authorized attacker to elevate privileges local Null pointer dereference in Windows Kernel allows an authorized attacker to elevate privileges locally.

CVE-2026-40378 [HIGH] CWE-789 CVE-2026-40378: Memory allocation with excessive size value in Windows Local Security Authority Subsystem Service (L Memory allocation with excessive size value in Windows Local Security Authority Subsystem Service (LSASS) allows an unauthorized attacker to deny service over a network.

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-2026-58529 [HIGH] CWE-125 CVE-2026-58529: Out-of-bounds read in Active Directory Federation Services (AD FS) allows an authorized attacker to Out-of-bounds read in Active Directory Federation Services (AD FS) allows an authorized attacker to disclose information over a network.

CVE-2026-50364 [HIGH] CWE-59 CVE-2026-50364: Improper link resolution before file access ('link following') in Windows Server Backup allows an au Improper link resolution before file access ('link following') in Windows Server Backup allows an authorized attacker to elevate privileges locally.

CVE-2026-32149 [HIGH] CWE-20 CVE-2026-32149: 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.