Critical Microsoft Vulnerability CVE-2026-23220 Requires Immediate Patching

Microsoft has released security updates addressing a critical vulnerability, CVE-2026-23220, which could allow attackers to execute arbitrary code on affected systems. The vulnerability carries a CVSS score of 9.8, indicating critical severity.

Affected products include:

• Windows 10 Version 21H2 and later
• Windows 11 Version 22H2 and later
• Microsoft Office 2021
• Microsoft 365 Apps for Enterprise

The vulnerability exists in the way Microsoft Windows handles objects in memory. An attacker who successfully exploited this vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system.

Microsoft has released security updates to address this vulnerability. Users are urged to apply the updates immediately. The updates are available through Windows Update and the Microsoft Update Catalog.

For systems that cannot be updated immediately, Microsoft recommends implementing workarounds such as enabling Enhanced Mitigation Experience Toolkit (EMET) or deploying additional network restrictions.

The vulnerability was reported to Microsoft by an external researcher. Microsoft is not aware of any attacks attempting to exploit this vulnerability at this time.

Organizations should prioritize patching systems that are exposed to the internet. The security updates will be automatically deployed through Windows Update for consumer devices. Enterprise customers should test updates in a non-production environment before deployment.

Additional information about CVE-2026-23220 can be found in Microsoft's Security Update Guide.