Microsoft October/November security updates

October 2026 Security Updates

This release consists of the following 1413 Microsoft CVEs:
Product Family Vulnerabilities Addressed Distinct Updates Update Type
Windows 1102 39 Cumulative
Office 134 11 Cumulative
SharePoint Server 36 1 Cumulative
SQL Server 22 8 Cumulative
Exchange Server 7 8 Cumulative
Developer Tools (Dev Div) 61 60 Mixed
Azure 15 20 Individual
Defender 4 3 Automatic
Edge 0 1 Automatic
Other 32 25 Individual
Total 1414 176

Notable CVEs
CVE ID Title Notable Item
CVE-2026-96951 Windows Shell Security Feature Bypass Vulnerability Exploitation Detected
CVE-2026-108398 .NET Framework Security Feature Bypass Vulnerability Publicly disclosed

We are republishing 1 non-Microsoft CVE:
CNA CVE ID Title
Cisco Talos CVE-2026-21413 Raw Image Extension Remote Code Execution Vulnerability

Security Update Guide Blog Posts
Date Blog Post
October 31, 2025 You asked, we delivered: Introducing new features for an improved security experience
October 28, 2025 Understanding CVE-2025-55315: What CISOs, security engineers, and sysadmins should know
October 22, 2025 Toward greater transparency: Introducing machine-readable Vulnerability Exploitability Xchange (VEX) for Azure Linux and beyond
November 12, 2024 Toward greater transparency: Publishing machine-readable CSAF files
June 27, 2024 Toward greater transparency: Unveiling Cloud Service CVEs
April 9, 2024 Toward greater transparency: Security Update Guide now shares CWEs for CVEs

Relevant Resources

• The new Hotpatching feature is now generally available. Please see Hotpatching feature for Windows Server Azure Edition virtual machines (VMs) for more information.
• Windows 10 and Windows 11 updates are cumulative. The monthly security release includes all security fixes for vulnerabilities that affect Windows 10 and Windows 11, in addition to non-security updates. The updates are available via the Microsoft Update Catalog. For information on lifecycle and support dates for Windows 10 and Windows 11 operating systems, please see Windows Lifecycle Facts Sheet.
• Microsoft is improving Windows Release Notes. For more information, please see What's next for Windows release notes.
• A list of the latest servicing stack updates for each operating system can be found in ADV990001. This list will be updated whenever a new servicing stack update is released. It is important to install the latest servicing stack update.
• In addition to security changes for the vulnerabilities, updates include defense-in-depth updates to help improve security-related features.
• Customers running Windows Server 2008 R2, or Windows Server 2008 need to purchase the Extended Security Update to continue receiving security updates. See 4522133 for more information.

Known Issues
You can see these in more detail from the Deployments tab by selecting Known Issues column in the Edit Columns panel.

For more information about Windows Known Issues, please see Windows message center (links to currently-supported versions of Windows are in the left pane).

KB Article Applies To
5126646 Windows Server 2025
5126651 Windows 10, version 1809, Windows Server 2019
5126655 Windows Server 2022
5126657 Windows 10 versions 21H2 and 22H2
5126868 Windows 10 version 1607, Windows Server 2016
5126934 SQL Server 2022 CU27 (Windows and Linux)
5126967 SQL Server 2025 CU9 (Windows and Linux)
5127646 Windows 11 version 26H1
5127648 Windows 11 version 26H2, Windows 11 version 25H2, Windows 11 version 24H2
5128492 SQL Server 2025 GDR (Windows and Linux)
5128493 SQL Server 2022 GDR (Windows and Linux)
5128494 SQL Server 2019 CU32 (Windows and Linux)
5128495 SQL Server 2019 GDR (Windows and Linux)
5128496 SQL Server 2017 CU31 (Windows and Linux)
5128497 SQL Server 2017 GDR (Windows and Linux)
5129955 Exchange Server SE
5129956 Exchange Server 2019 CU15
5129957 Exchange Server 2019 CU14
5129958 Exchange Server 2016 CU23
Released: Oct 13, 2026
October 2026 Security Updates - Release Notes - Security Update Guide - Microsoft