KB5066872: Overview with user sentiment and feedback

Overview

This security update for Windows Server 2008 R2 includes fixes and quality improvements that are part of the September 9, 2025 - KB5065468 (Monthly Rollup) update. The key changes in this update are:- Removal of the ltmdm64.sys fax modem driver, meaning fax modem hardware dependent on this driver will no longer work.- Security hardening by requiring the use of Key Storage Provider (KSP) instead of Cryptographic Service Provider (CSP) for RSA-based smart card certificates. This may cause issues with smart card authentication that will require resolution steps.- Automatic disabling of the File Explorer preview feature for files downloaded from the internet, to enhance security and prevent vulnerabilities when previewing potentially unsafe files.This update also includes the resolution of various security vulnerabilities. Users should review the Deployments | Security Update Guide and the October 2025 Security Updates for more details on the resolved issues.

General Purpose

The primary purpose of this Windows Server 2008 R2 security update is to address several security vulnerabilities and make security improvements to the operating system. The key changes include:- Removal of the ltmdm64.sys fax modem driver, which will impact fax modem functionality on affected systems.- Requirement to use Key Storage Provider (KSP) instead of Cryptographic Service Provider (CSP) for RSA-based smart card certificates, which may cause authentication issues that require resolution.- Automatic disabling of the File Explorer preview feature for files downloaded from the internet, to enhance security and prevent vulnerabilities when previewing potentially unsafe files.In addition to these changes, the update also includes various other security fixes and quality improvements as part of the cumulative September 2025 Monthly Rollup. Users should review the security update details to understand the full scope of changes and potential impacts.

General Sentiment

The sentiment around this Windows Server 2008 R2 security update is mixed. On the positive side, the update addresses several known security vulnerabilities, which is important for maintaining the security and integrity of affected systems. The automatic disabling of the File Explorer preview feature for downloaded files is also a welcome security enhancement.However, the removal of the ltmdm64.sys fax modem driver and the requirement to use KSP instead of CSP for smart card certificates may cause disruptions for some users. There are reports of smart card authentication issues arising from the cryptography changes, which will require troubleshooting and resolution steps.Overall, the update appears necessary from a security standpoint, but the potential impact on fax modem functionality and smart card authentication is a concern that users will need to carefully evaluate and prepare for. Thorough testing and planning is advised before deploying this update, especially for environments heavily reliant on these affected features.

Known Issues

• Removal of the ltmdm64.sys fax modem driver may impact fax modem hardware dependent on this driver, causing loss of functionality.- Requirement to use Key Storage Provider (KSP) instead of Cryptographic Service Provider (CSP) for RSA-based smart card certificates may cause authentication issues that require resolution steps.

Disclaimer: We take measures to ensure that AI-generated content is of the highest possible quality, but we cannot guarantee its accuracy and recommend that users do their own independent research. Generated on 2025-11-30 07:05 PM

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