Microsoft’s Patch Tuesday fixes 175 vulnerabilities, including two actively exploited zero-days

Microsoft addressed 175 vulnerabilities affecting its core products and underlying systems, including two actively exploited zero-days, the company said in its latest security update. It’s the largest assortment of defects disclosed by the tech giant this year.

The zero-day vulnerabilities — CVE-2025-24990 affecting Agere Windows Modem Driver and CVE-2025-59230 affecting Windows Remote Access Connection Manager — both have a CVSS rating of 7.8. The Cybersecurity and Infrastructure Security Agency added both zero-days to its known exploited vulnerabilities catalog Tuesday.

Microsoft said the third-party Agere Modem drive that ships with supported Windows operating systems has been removed in the October security update. Fax modem hardware that relies on the driver will no longer work on Windows, the company said.

Attackers can achieve administrator privileges by exploiting CVE-2025-24990. “All supported versions of Windows can be affected by a successful exploitation of this vulnerability, even if the modem is not actively being used,” Microsoft said in its summary of the defect.

The improper access control vulnerability affecting Windows Remote Access Connection manager can be exploited by an authorized attacker to elevate privileges locally and gain system privileges, Microsoft said. 

Windows Remote Access Connection Manager, a service used to manage remote network connections through virtual private networks and dial-up networks, is a “frequent flyer on Patch Tuesday, appearing more than 20 times since January 2022,” Satnam Narang, senior staff research engineer at Tenable, said in an email. “This is the first time we’ve seen it exploited in the wild as a zero day.”

The most severe vulnerabilities disclosed this month include CVE-2025-55315 affecting ASP.NET core and CVE-2025-49708 affecting Microsoft Graphics Component. Microsoft said exploitation of the defects is less likely, but both have a CVSS rating of 9.9.

Microsoft flagged 14 defects as more likely to be exploited this month, including a pair of critical vulnerabilities with CVSS ratings of 9.8 — CVE-2025-59246 affecting Azure Entra ID and CVE-2025-59287 affecting Windows Server Update Service.

The vendor disclosed five critical and 121 high-severity vulnerabilities this month. The full list of vulnerabilities addressed this month is available in Microsoft’s Security Response Center.