Microsoft Releases Largest Patch Tuesday Yet: 167 CVEs Addressed in October 2025
Microsoft’s October 2025 Patch Tuesday marks a milestone: it is the company’s largest release to date, addressing 167 distinct CVEs across a wide array of products and services. Among these are three zero-day vulnerabilities, including two actively exploited, and critical updates relevant to enterprise and cloud environments. This comprehensive patch release reflects Microsoft’s ongoing response to rapidly evolving exploitation trends.
Scope and Scale of the Update
The October 2025 update remediates 167 CVEs with seven rated as critical in severity. An additional 158 are ranked important and two are considered moderate. The update also omits 27 other advisories focused on external ecosystems, such as Chromium, MITRE, GitHub, CERT/CC, and multiple cloud-specific vulnerabilities, highlighting Microsoft’s increased integration of third-party tracking into its vulnerability management process.
Zero-Day Vulnerabilities and Exploitation Trends
Of particular concern are three zero-day vulnerabilities, with two verified as having been exploited in the wild. Microsoft has prioritized these in its deployment guidance due to the elevated risk of targeted attacks. This trend underscores the necessity for urgent patch cycling and the continual need for organizations to adapt their security postures to new active threats.
Focus: CVE-2025-55680—Windows Cloud Files Mini Filter Driver Elevation of Privilege
CVE-2025-55680 highlights persistent risks within the Windows Cloud Files Mini Filter Driver. This elevation of privilege (EoP) vulnerability is assigned a CVSS score of 7.8 and categorized as “Exploitation More Likely.” To exploit, a local authenticated attacker must win a race condition, allowing a privilege elevation to SYSTEM. This flaw demonstrates recurring exposure in the Cloud Files Mini Filter Driver, which has been patched 17 times since 2022, showing a consistent target for attackers seeking advanced lateral movement or local exploitation opportunities within Windows environments.
Windows 10 End of Support: Security Implications
As of October 14, 2025, Windows 10 has officially reached its end of support lifecycle. Microsoft will no longer provide free security updates, technical support, or software patches for this operating system version. Enterprise users are now required to enroll in the Extended Security Updates (ESU) program to maintain security coverage. Both the original Windows 10 Enterprise 2015 LTSB and Windows 10 IoT Enterprise LTSB 2015 have also reached end-of-life, amplifying cybersecurity risks for organizations that have not yet transitioned to supported platforms. Plugins are available to assist organizations in identifying unsupported deployments, thereby facilitating remediation planning and migration to newer, actively supported Windows versions.