Microsoft Patch Tuesday Update September 2026 – 974 Vulnerabilities Fixed, Including 2 Zero-Days
Microsoft's September 2026 Patch Tuesday fixes 974 vulnerabilities across Windows and Office, including two actively exploited Windows privilege-escalation zero-days.
Microsoft's September 2026 Patch Tuesday addresses 974 vulnerabilities spanning Windows, Office, SQL Server, SharePoint, Exchange, Azure, and developer tools. Two Windows zero-days are confirmed exploited in attacks: CVE-2026-85880, a Windows ALPC elevation-of-privilege flaw, and CVE-2026-81963, a Windows Update Stack privilege-escalation flaw involving link following. The release also includes Critical fixes for Windows Secure Kernel Mode, VBS Enclave, Excel, and Word.
Microsoft: Windows Server 2025 changes causing app crashes
Microsoft warns Windows Server 2025 memory-management changes crash AWE apps, including SQL Server with Lock Pages in Memory; disable LPIM as workaround.
Microsoft confirmed a known issue where Windows Server 2025 memory-management changes cause access violations, memory corruption, or unexpected termination in applications using Address Windowing Extensions (AWE). SQL Server running with the Lock Pages in Memory (LPIM) policy is affected, with symptoms including 0xC0000005 access violations, DBCC CHECKDB failures, crash dumps, and services stopping or restarting unexpectedly. Microsoft's temporary workaround is to disable the LPIM policy for the SQL Server service account or disable AWE in other affected apps, with a permanent fix promised in a future Windows update.
Microsoft’s Biggest Patch Tuesday: 974 CVEs, 2 Zero-Days and 20 Wormable Bugs
Microsoft's record September 2026 Patch Tuesday fixes 974 CVEs, including two exploited Windows privilege-escalation zero-days and 20 wormable bugs.
Microsoft's September 2026 Patch Tuesday fixes a record 974 CVEs, including two actively exploited zero-days: CVE-2026-85880, an ALPC heap buffer overflow, and CVE-2026-81963 in the Windows Update Stack, both CVSS 7.8 local privilege escalations. It also addresses an unauthenticated Exchange RCE (CVE-2026-55007) triggered by Visio attachment content indexing under memory pressure, an RDP use-after-free (CVE-2026-69525, CVSS 9.8), and 20 wormable flaws in DNS, DHCP, SMB, Active Directory, and other components. ZDI attributed the rising volume partly to AI-assisted vulnerability discovery, noting no corresponding spike in active exploits yet.