Article
October 2025 Patch Tuesday: Key Vulnerabilities Overview
Introduction
October’s Patch Tuesday delivers another extensive round of security fixes across Microsoft’s product ecosystem, addressing multiple critical vulnerabilities in Windows, Office, and Azure services. This month also marks a major milestone: it’s the final round of security updates for Windows 10 systems, as Microsoft officially sunsets support for the OS after ten years. Organizations still running Windows 10 should prioritize migration planning to maintain protection against emerging threats.
Summary of October 2025 Patch Tuesday
October’s Patch Tuesday addresses a large number of security weaknesses across many Microsoft products. Some issues are more severe than others, with a few posing significant risks if not fixed. Notable problems involve areas like web servers and online services, which if left undefended, can be open to cyber-attacks. Keeping software updated is essential to guard against these potential threats.
Understanding these updates is crucial in protecting enterprise environments. Below, we categorize the vulnerabilities based on their exposure to the internet.
Updates are listed according to their CVSS Score
Exposed to internet
October 2025 Patch Tuesday
Internal Network
Microsoft Closes the Book on Windows 10 Updates
Exposed to the Internet
Microsoft Graphics Component – Elevation of Privilege
Microsoft Graphics Component, which handles the rendering of graphics in Windows applications, has a vulnerability that could allow Elevation of Privilege through remote code execution. This could lead to system compromise if exploited by attackers.
Windows Server Update Service – Remote Code Execution
Windows Server Update Service (WSUS) allows administrators to manage Microsoft update distribution. An unsafe deserialization vulnerability in WSUS could enable Remote Code Execution attacks by unauthenticated users, posing a critical risk to server security.
AMD EPYC Processors – Memory Integrity Vulnerability
AMD EPYC processors utilize Secure Encrypted Virtualization (SEV) to provide secure, hardware-isolated environments. A vulnerability impacting SEV-SNP compromises the ability of these processors to maintain memory integrity, which could undermine system security.
Microsoft Office – Remote Code Execution
Microsoft Office, a suite of productivity applications like Word, Excel, and PowerPoint, is vulnerable to Remote Code Execution due to a use-after-free error. This exploit could be triggered via malicious files, leading to potential system compromise.
Internal Network
Windows Remote Access Connection Manager – Elevation of Privilege
The Windows Remote Access Connection Manager (RASMan) service manages dial-up and VPN connections, ensuring secure remote network access. An Elevation of Privilege vulnerability exists in RASMan, which could be exploited to escalate privileges without proper authorization, compromising system security.
Software Protection Platform – Elevation of Privilege
The Software Protection Platform, responsible for Microsoft product licensing and activation, has an Elevation of Privilege vulnerability due to improper access control. This flaw could allow unauthorized local privilege escalation on vulnerable systems.
Agere Windows Modem Driver – Elevation of Privilege
The Agere Windows Modem Driver, which facilitates communication between a computer and Agere modems in supported Windows operating systems, is vulnerable to an Elevation of Privilege exploit. This vulnerability could be exploited through a third-party modem driver, potentially granting unauthorized elevated permissions on a system.
Agere Windows Modem Driver – Elevation of Privilege
The Agere Windows Modem Driver, supporting modem functionalities on various Windows systems, has a vulnerability similar to CVE-2025-24990. It could allow Elevation of Privilege, potentially affecting systems even if they do not utilize modem features.
TCG TPM2.0 – Out-of-Bounds Read
The Trusted Platform Module (TPM) 2.0, which provides hardware-based security functions, is found to have an Out-of-Bounds read vulnerability. This flaw could potentially lead to information disclosure by allowing unauthorized reading of memory locations.
IGEL OS – Secure Boot Bypass
IGEL OS is a Linux-based operating system designed for thin clients often used in virtualized environments. A Secure Boot Bypass vulnerability in IGEL OS may allow the execution of unauthorized crafted root filesystems, posing a significant security risk.
Conclusion
October’s updates close a significant chapter for Microsoft environments. Alongside patches for actively exploited vulnerabilities, this release concludes the security lifecycle for Windows 10, underscoring the urgency for enterprises to transition to supported versions such as Windows 11. As attackers increasingly target legacy platforms, maintaining visibility into unsupported assets and enforcing compensating controls will be key to sustaining security posture through Q4 and beyond.
Have questions about implementing these patches or securing your IT environment? Schedule a call with At-Bay’s Advisory Services team to get started.
About CVSS
The Common Vulnerability Scoring System (CVSS) is an industry-standard framework for evaluating and communicating the severity of software vulnerabilities. It provides a numerical score that helps organizations prioritize and address security issues effectively. CVSS scores quantify the severity of a vulnerability on a scale from 0 (no severity) to 10 (critical severity). CVSS considers multiple factors, including; Exploitability, Impact, Exploit code maturity, Remediation level, Report confidence. The system enables organizations to compare and prioritize vulnerabilities based on their potential impact on IT infrastructure.
References
- https://msrc.microsoft.com/update-guide/releasenote/2025-oct
- https://www.rapid7.com/blog/post/em-patch-tuesday-october-2025/
- https://www.bleepingcomputer.com/news/microsoft/microsoft-october-2025-patch-tuesday-fixes-6-zero-days-172-flaws/
- https://krebsonsecurity.com/2025/10/patch-tuesday-october-2025-end-of-10-edition/
- https://blog.qualys.com/vulnerabilities-threat-research/2025/10/14/microsoft-patch-tuesday-october-2025-security-update-review