Microsoft Windows Server 2012 R2 vulnerabilities

CVE-2026-20831 [HIGH] CWE-367 CVE-2026-20831: Time-of-check time-of-use (toctou) race condition in Windows Ancillary Function Driver for WinSock a Time-of-check time-of-use (toctou) race condition in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

CVE-2026-20919 [HIGH] CWE-362 CVE-2026-20919: Concurrent execution using shared resource with improper synchronization ('race condition') in Windo Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.

CVE-2026-20931 [HIGH] CWE-73 CVE-2026-20931: External control of file name or path in Windows Telephony Service allows an authorized attacker to External control of file name or path in Windows Telephony Service allows an authorized attacker to elevate privileges over an adjacent network.

CVE-2026-20809 [HIGH] CWE-122 CVE-2026-20809: Time-of-check time-of-use (toctou) race condition in Windows Kernel Memory allows an authorized atta Time-of-check time-of-use (toctou) race condition in Windows Kernel Memory allows an authorized attacker to elevate privileges locally.

CVE-2026-20868 [HIGH] CWE-122 CVE-2026-20868: Heap-based buffer overflow in Windows Routing and Remote Access Service (RRAS) allows an unauthorize Heap-based buffer overflow in Windows Routing and Remote Access Service (RRAS) allows an unauthorized attacker to execute code over a network.

CVE-2026-20929 [HIGH] CWE-284 CVE-2026-20929: Improper access control in Windows HTTP.sys allows an authorized attacker to elevate privileges over Improper access control in Windows HTTP.sys allows an authorized attacker to elevate privileges over a network.

CVE-2026-20934 [HIGH] CWE-362 CVE-2026-20934: Concurrent execution using shared resource with improper synchronization ('race condition') in Windo Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.

CVE-2026-20820 [HIGH] CWE-122 CVE-2026-20820: Heap-based buffer overflow in Windows Common Log File System Driver allows an authorized attacker to Heap-based buffer overflow in Windows Common Log File System Driver allows an authorized attacker to elevate privileges locally.

CVE-2026-20940 [HIGH] CWE-822 CVE-2026-20940: Heap-based buffer overflow in Windows Cloud Files Mini Filter Driver allows an authorized attacker t Heap-based buffer overflow in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.

CVE-2026-0386 [HIGH] CWE-284 CVE-2026-0386: Improper access control in Windows Deployment Services allows an unauthorized attacker to execute co Improper access control in Windows Deployment Services allows an unauthorized attacker to execute code over an adjacent network.

CVE-2026-20805 [MEDIUM] CWE-200 CVE-2026-20805: Exposure of sensitive information to an unauthorized actor in Desktop Windows Manager allows an auth Exposure of sensitive information to an unauthorized actor in Desktop Windows Manager allows an authorized attacker to disclose information locally.

CVE-2026-20839 [MEDIUM] CWE-284 CVE-2026-20839: Improper access control in Windows Client-Side Caching (CSC) Service allows an authorized attacker t Improper access control in Windows Client-Side Caching (CSC) Service allows an authorized attacker to disclose information locally.

CVE-2026-20824 [MEDIUM] CWE-693 CVE-2026-20824: Protection mechanism failure in Windows Remote Assistance allows an unauthorized attacker to bypass Protection mechanism failure in Windows Remote Assistance allows an unauthorized attacker to bypass a security feature locally.

CVE-2026-21265 [MEDIUM] CWE-1329 CVE-2026-21265: Windows Secure Boot stores Microsoft certificates in the UEFI KEK and DB. These original certificate Windows Secure Boot stores Microsoft certificates in the UEFI KEK and DB. These original certificates are approaching expiration, and devices containing affected certificate versions must update them to maintain Secure Boot functionality and avoid compromising security by losing security fixes related to Windows boot manager or Secure Boot. The ope

CVE-2026-20847 [MEDIUM] CWE-200 CVE-2026-20847: Exposure of sensitive information to an unauthorized actor in Windows Shell allows an authorized att Exposure of sensitive information to an unauthorized actor in Windows Shell allows an authorized attacker to perform spoofing over a network.

CVE-2026-20872 [MEDIUM] CWE-73 CVE-2026-20872: 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 over a network.

CVE-2026-20821 [MEDIUM] CWE-200 CVE-2026-20821: Exposure of sensitive information to an unauthorized actor in Windows Remote Procedure Call allows a Exposure of sensitive information to an unauthorized actor in Windows Remote Procedure Call allows an unauthorized attacker to disclose information locally.

CVE-2026-20925 [MEDIUM] CWE-73 CVE-2026-20925: 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 over a network.

CVE-2026-20936 [MEDIUM] CWE-125 CVE-2026-20936: Out-of-bounds read in Windows NDIS allows an authorized attacker to disclose information with a phys Out-of-bounds read in Windows NDIS allows an authorized attacker to disclose information with a physical attack.

CVE-2026-20834 [MEDIUM] CWE-36 CVE-2026-20834: Absolute path traversal in Windows Shell allows an unauthorized attacker to perform spoofing with a Absolute path traversal in Windows Shell allows an unauthorized attacker to perform spoofing with a physical attack.