Microsoft Releases Security Patches for Multiple Vulnerabilities

The Cyber Security Agency of Singapore issued an alert on 11 November 2026 regarding security patches released by Microsoft to address multiple vulnerabilities across its software and products. Multiple vulnerabilities have been classified as Critical in severity, presenting remote code execution and elevation of privilege risks across platforms including Windows, Microsoft Office, and cloud services. Malaysian organisations and users experiencing suspected cybersecurity incidents can seek assistance from Cyber999.

Key Facts

Which Vulnerabilities Pose the Highest Risk?

The highest-rated vulnerability is CVE-2026-109469, an elevation of privilege flaw in Entra Device Registration carrying a maximum CVSS base score of 10.0. Four other flaws follow closely with scores of 9.8, affecting the Windows Xbox Live Networking Service, Windows Search, Windows LDAP, and Azure OpenAI services.

A CVSS base score of 10.0 represents the highest possible severity rating, indicating critical impact across affected directory registrations. In addition to CVE-2026-109469, Microsoft identified remote code execution flaws in core operating system services, including Windows Search (CVE-2026-116928) and Windows LDAP (CVE-2026-119958), as well as an elevation of privilege flaw in Azure OpenAI (CVE-2026-119990) and remote execution in the Xbox Live Networking Service (CVE-2026-112967), all evaluated at a base score of 9.8.

CVE-2026-109469 in Entra Device Registration carries a maximum CVSS base score of 10.0.

Which Productivity and Core Services Are Impacted?

Microsoft's November 2026 release impacts widespread software environments, including Microsoft Office applications, Microsoft Defender, Microsoft Exchange Server, and Windows Hyper-V. Multiple remote code execution vulnerabilities carrying base scores of 8.8 affect Word, Excel, PowerPoint, and Outlook, while additional critical issues reside in Windows Message Queuing and kernel components.

The advisory lists extensive vulnerabilities across business productivity suites, including twelve distinct remote code execution vulnerabilities in Microsoft Office Excel and three in Microsoft Office Outlook, each assigned a base score of 8.8. Core infrastructure is similarly impacted, with remote code execution flaws affecting Active Directory Domain Services (CVE-2026-118146) and Microsoft Exchange Server (CVE-2026-118207), alongside numerous elevation of privilege flaws across Windows Hyper-V.

Numerous remote code execution vulnerabilities across Microsoft Word, Excel, PowerPoint, and Outlook hold critical CVSS base scores of 8.8.

What Should You Do?

• Apply the official security patches released by Microsoft to address these vulnerabilities across all affected software and products.
• Verify system updates across Microsoft Windows, Microsoft Office installations, Exchange Server, and cloud-connected device services.
• Malaysian organisations and individuals who detect anomalies or suspect security incidents can report them to the Cyber999 incident response centre managed by MyCERT.

Common Questions

What is the most critical vulnerability reported in this patch release?

The most critical vulnerability is CVE-2026-109469, an Entra Device Registration Elevation of Privilege Vulnerability, which has received a maximum CVSS base score of 10.0. It is classified under Critical severity in the advisory issued by the Cyber Security Agency of Singapore.

Are remote code execution vulnerabilities present in Microsoft Office?

Yes, multiple remote code execution vulnerabilities affect Microsoft Office components, including Word, Excel, PowerPoint, and Outlook. Many of these flaws carry a CVSS base score of 8.8, highlighting a critical risk across productivity applications used in corporate and individual systems.

Where can users obtain the official security patches?

Users should apply the official security updates released by Microsoft for their specific systems and software. System administrators should ensure all affected software components and operating system services are promptly updated using vendor-supported patching channels.

Sources and Methodology

This dispatch is based solely on the advisory published by the Cyber Security Agency of Singapore on 11 November 2026. No external vendor documentation, secondary advisories, or unverified reports were reviewed or consulted for this summary.