Critical Microsoft Vulnerability CVE-2026-28388 Requires Immediate Patching

Microsoft has released security updates to address a critical vulnerability that could allow attackers to execute arbitrary code on affected systems. CVE-2026-28388 carries a CVSS score of 9.8, indicating critical severity.

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.

Affected products include:

• Windows 10 Version 1809 and later
• Windows 11 Version 21H2 and later
• Windows Server 2019 and later
• Microsoft Office 2019 and Microsoft 365 Apps

Microsoft has released security updates on the second Tuesday of December 2025 as part of their regular Patch Tuesday cycle. Organizations should apply these updates immediately.

Mitigation steps:

1. Apply the security updates provided by Microsoft
2. Enable automatic updates on all systems
3. Implement network segmentation to limit lateral movement
4. Use application control solutions to prevent unauthorized code execution
5. Monitor for suspicious activity related to memory exploitation

For detailed information on the specific updates, visit the Microsoft Security Response Center. The official security advisory contains additional technical details and workarounds if immediate patching is not possible.

Organizations unable to patch immediately should implement Microsoft's recommended workarounds, which include disabling the affected components and implementing additional network restrictions. However, these workarounds may impact system functionality and should be considered temporary measures.