Microsoft’s February 2026 Patch Tuesday: Addressing 59 Vulnerabilities, Including Six Actively Exploited Zero-Days
On February 10, 2026, Microsoft released its monthly Patch Tuesday updates, addressing 59 security vulnerabilities across various products. This release is particularly significant due to the inclusion of six zero-day vulnerabilities that have been actively exploited in the wild.
Overview of the Vulnerabilities
The 59 vulnerabilities are categorized as follows:
– Severity Levels:
– 5 Critical
– 52 Important
– 2 Moderate
– Types of Vulnerabilities:
– 25 Elevation of Privilege
– 12 Remote Code Execution
– 7 Spoofing
– 6 Information Disclosure
– 5 Security Feature Bypass
– 3 Denial of Service
– 1 Cross-Site Scripting
Details on the Actively Exploited Zero-Day Vulnerabilities
1. CVE-2026-21510 – Windows Shell Security Feature Bypass Vulnerability
– Description: This vulnerability allows attackers to bypass Windows SmartScreen and Shell security warnings by convincing users to open specially crafted links or shortcut files.
– Impact: Successful exploitation enables the execution of malicious content without triggering security prompts.
– Severity: Important (CVSS score: 8.8)
2. CVE-2026-21513 – MSHTML Framework Security Feature Bypass Vulnerability
– Description: An attacker can exploit this flaw by persuading a user to open a malicious HTML or shortcut file, leading to the bypass of execution prompts.
– Impact: This can result in the execution of attacker-controlled content without user warnings.
– Severity: Important (CVSS score: 8.8)
3. CVE-2026-21514 – Microsoft Word Security Feature Bypass Vulnerability
– Description: By opening a specially crafted Office document, a user may inadvertently allow Word to make security decisions based on untrusted input.
– Impact: This undermines protections designed to block risky COM/OLE behavior.
– Severity: Important (CVSS score: 7.8)
4. CVE-2026-21519 – Desktop Window Manager Elevation of Privilege Vulnerability
– Description: This vulnerability allows an authenticated attacker to gain SYSTEM-level privileges through a type confusion flaw in the Desktop Window Manager.
– Impact: Successful exploitation can lead to full control over the affected system.
– Severity: Important (CVSS score: 7.8)
5. CVE-2026-21525 – Windows Remote Access Connection Manager Denial of Service Vulnerability
– Description: A local attacker can exploit this null pointer dereference vulnerability to cause a denial-of-service condition.
– Impact: Repeated exploitation can lead to persistent service disruption.
– Severity: Moderate (CVSS score: 6.2)
6. CVE-2026-21533 – Windows Remote Desktop Services Elevation of Privilege Vulnerability
– Description: This flaw allows an authenticated attacker to elevate privileges within Windows Remote Desktop Services.
– Impact: Exploitation can result in unauthorized access and control over the system.
– Severity: Important (CVSS score: 7.8)
Additional Critical Vulnerabilities
Beyond the zero-days, Microsoft addressed five Critical-rated vulnerabilities this month:
1. Azure Compute Infrastructure (ACI) Confidential Containers Vulnerabilities
– CVE-2026-24302 & CVE-2026-24300: Remote code execution flaws.
– CVE-2026-21532: Elevation of privilege vulnerability.
– Note: Microsoft indicates that these require no customer action.
2. CVE-2026-21522 – ACI Confidential Containers Elevation of Privilege Vulnerability
– Description: An elevation of privilege issue within ACI Confidential Containers.
– Severity: Critical (CVSS score: 6.7)
3. CVE-2026-23655 – Information Disclosure Vulnerability
– Description: This flaw could expose sensitive tokens and keys.
– Severity: Critical (CVSS score: 6.5)
Recommendations for Users and Administrators
Given the active exploitation of these vulnerabilities, it is imperative for users and administrators to:
– Apply Updates Promptly: Ensure that all systems are updated with the latest patches to mitigate potential threats.
– Educate Users: Inform users about the risks associated with opening unsolicited links or documents, emphasizing caution even if they appear to come from trusted sources.
– Monitor Systems: Regularly review system logs and network activity for signs of unusual behavior that may indicate exploitation attempts.
– Implement Security Best Practices: Utilize multi-factor authentication, maintain regular backups, and employ endpoint protection solutions to enhance overall security posture.
Conclusion
Microsoft’s February 2026 Patch Tuesday underscores the ongoing challenges in cybersecurity, highlighting the importance of timely updates and proactive security measures. By addressing these vulnerabilities promptly, organizations can significantly reduce the risk of exploitation and maintain a secure computing environment.
