KB5099444: what it fixes and who gets it
KB5099444 is a monthly rollup from Microsoft's July 2026 release for Windows Server 2012 R2.
Microsoft data read
Should you install it?
Yes, and soon: it closes a hole that was already being used in real attacks before the fix was released. Windows Update installs it automatically on supported home PCs.
If the installation fails or the PC misbehaves afterwards, note the exact error code first: the fix depends on it. Our update troubleshooting guides are linked on this page.
Security fixes in KB5099444
| CVE | Type | CVSS | Severity |
|---|---|---|---|
| CVE-2026-56155Active Directory Federation Services Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | ExploitedImportant |
| CVE-2026-57092Microsoft Windows VMSwitch Elevation of Privilege Vulnerability | Elevation of Privilege | 9.9 | Critical |
| CVE-2026-50518Windows DHCP Server Remote Code Execution Vulnerability | Remote Code Execution | 9.8 | Critical |
| CVE-2026-56159DHCP Server Service Remote Code Execution Vulnerability | Remote Code Execution | 9.8 | Critical |
| CVE-2026-56188Windows Server Network driver Remote Code Execution Vulnerability | Remote Code Execution | 9.8 | Critical |
| CVE-2026-50380Windows GDI+ Remote Code Execution Vulnerability | Remote Code Execution | 9.6 | Critical |
| CVE-2026-50370DHCP Server Service Remote Code Execution Vulnerability | Remote Code Execution | 8.8 | Critical |
| CVE-2026-50444Windows Server Update Service (WSUS) Elevation of Privilege Vulnerability | Elevation of Privilege | 8.8 | Critical |
| CVE-2026-50474Remote Desktop Client Remote Code Execution Vulnerability | Remote Code Execution | 8.8 | Critical |
| CVE-2026-54121Active Directory Certificate Services Elevation of Privilege Vulnerability | Elevation of Privilege | 8.8 | Critical |
| CVE-2026-54982Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability | Remote Code Execution | 8.8 | Critical |
| CVE-2026-54999Windows TCP/IP Remote Code Execution Vulnerability | Remote Code Execution | 8.8 | Critical |
| CVE-2026-58608Windows Print Spooler Remote Code Execution Vulnerability | Remote Code Execution | 8.8 | Critical |
| CVE-2026-54128Windows DHCP Client Remote Code Execution Vulnerability | Remote Code Execution | 8.4 | Critical |
| CVE-2026-54992Microsoft Message Queuing Queue Manager Remote Code Execution Vulnerability | Remote Code Execution | 8.4 | Critical |
| CVE-2026-49164Windows Active Directory Domain Services Remote Code Execution Vulnerability | Remote Code Execution | 8.1 | Critical |
| CVE-2026-50694Windows Secure Socket Tunneling Protocol (SSTP) Remote Code Execution Vulnerability | Remote Code Execution | 8.1 | Critical |
| CVE-2026-54995Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability | Remote Code Execution | 8.1 | Critical |
| CVE-2026-49796Windows GDI+ Remote Code Execution Vulnerability | Remote Code Execution | 7.8 | Critical |
| CVE-2026-56189Microsoft Windows Media Foundation Remote Code Execution Vulnerability | Remote Code Execution | 7.8 | Critical |
| CVE-2026-50447Windows Message Queuing Service (MSMQ) Remote Code Execution Vulnerability | Remote Code Execution | 9.8 | Important |
| CVE-2026-56190Remote Desktop Protocol Remote Code Execution Vulnerability | Remote Code Execution | 9.8 | Important |
| CVE-2026-49798Windows Kernel Elevation of Privilege Vulnerability | Elevation of Privilege | 9.3 | Important |
| CVE-2026-49178Windows Active Directory Domain Services Remote Code Execution Vulnerability | Remote Code Execution | 8.8 | Important |
| CVE-2026-50369Windows Remote Desktop Services Elevation of Privilege Vulnerability | Elevation of Privilege | 8.8 | Important |
| CVE-2026-50477Windows Kernel Elevation of Privilege Vulnerability | Elevation of Privilege | 8.8 | Important |
| CVE-2026-50489Win32k Elevation of Privilege Vulnerability | Elevation of Privilege | 8.8 | Important |
| CVE-2026-50666Windows Remote Access Elevation of Privilege Vulnerability | Elevation of Privilege | 8.8 | Important |
| CVE-2026-54107Windows Win32k Elevation of Privilege Vulnerability | Elevation of Privilege | 8.8 | Important |
| CVE-2026-56194Windows NFS Server Elevation of Privilege Vulnerability | Elevation of Privilege | 8.8 | Important |
| CVE-2026-56647Windows Remote Access Service Infrastructure Elevation of Privilege Vulnerability | Elevation of Privilege | 8.8 | Important |
| CVE-2026-58594Remote Desktop Client Remote Code Execution Vulnerability | Remote Code Execution | 8.8 | Important |
| CVE-2026-49184Windows NTFS Remote Code Execution Vulnerability | Remote Code Execution | 8.4 | Important |
| CVE-2026-54122Windows GDI+ Remote Code Execution Vulnerability | Remote Code Execution | 8.4 | Important |
| CVE-2026-50439Microsoft Message Queuing Queue Manager Remote Code Execution Vulnerability | Remote Code Execution | 8.1 | Important |
| CVE-2026-50686Windows OLE Remote Code Execution Vulnerability | Remote Code Execution | 8.1 | Important |
| CVE-2026-56186Windows Secure Channel Information Disclosure Vulnerability | Information Disclosure | 8.1 | Important |
| CVE-2026-40400Windows PowerShell Remote Code Execution Vulnerability | Remote Code Execution | 8.0 | Important |
| CVE-2026-42975Windows Bluetooth Port Driver Remote Code Execution | Remote Code Execution | 8.0 | Important |
| CVE-2026-50365Remote Access Management service/API (RPC server) Elevation of Privilege Vulnerability | Elevation of Privilege | 8.0 | Important |
| CVE-2026-50502Windows Event Logging Service Remote Code Execution Vulnerability | Remote Code Execution | 8.0 | Important |
| CVE-2026-50683Windows DHCP Client Elevation of Privilege Vulnerability | Elevation of Privilege | 8.0 | Important |
| CVE-2026-49797Windows NTFS Remote Code Execution Vulnerability | Remote Code Execution | 7.8 | Important |
| CVE-2026-50306Windows TCP/IP Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
| CVE-2026-50308Windows NTFS Remote Code Execution Vulnerability | Remote Code Execution | 7.8 | Important |
| CVE-2026-50309Windows NTFS Remote Code Execution Vulnerability | Remote Code Execution | 7.8 | Important |
| CVE-2026-50311Windows Server Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
| CVE-2026-50313Windows NTFS Remote Code Execution Vulnerability | Remote Code Execution | 7.8 | Important |
| CVE-2026-50321Windows USB Driver Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
| CVE-2026-50332Windows Kernel Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
| CVE-2026-50344Windows OLE Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
| CVE-2026-50346Netlogon RPC Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
| CVE-2026-50347Windows Data.dll Remote Code Execution Vulnerability | Remote Code Execution | 7.8 | Important |
| CVE-2026-50351Windows Audio Compression Manager (ACM) Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
| CVE-2026-50363Windows Push Notifications Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
| CVE-2026-50386Windows NTFS Remote Code Execution Vulnerability | Remote Code Execution | 7.8 | Important |
| CVE-2026-50387Windows GDI Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
| CVE-2026-50388Windows NTFS Remote Code Execution Vulnerability | Remote Code Execution | 7.8 | Important |
| CVE-2026-50391Windows Group Policy Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
| CVE-2026-50400Windows App Package Installer Elevation of Privilege Vulnerability | Elevation of Privilege | 7.8 | Important |
Showing the 60 most severe of 184. The full list is in Microsoft's Security Update Guide.
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