KB5066873: Overview with user sentiment and feedback

Overview

This security update for Windows Server 2012 R2 includes fixes and quality improvements that are part of the September 9, 2025 KB5065507 (Monthly Rollup) update. The key changes include addressing a stability issue that was causing some devices to become unresponsive, removing a fax modem driver that is no longer supported, and enforcing a security hardening improvement for RSA-based smart card certificates. Additionally, this update automatically disables the file preview feature in File Explorer for files downloaded from the internet to enhance security.

General Purpose

The main purpose of this KB5066873 update is to address several important issues in Windows Server 2012 R2. It fixes a stability problem that was causing some devices to become unresponsive after installing previous updates. It also removes support for a fax modem driver that is no longer needed, and it enforces a security improvement for RSA-based smart card certificates by requiring the use of the Key Storage Provider instead of the Cryptographic Service Provider. Additionally, this update automatically disables the file preview feature in File Explorer for downloaded internet files to prevent a potential security vulnerability.

General Sentiment

The overall sentiment towards this KB5066873 update appears to be positive, as it addresses several important stability and security issues that were impacting Windows Server 2012 R2 systems. The removal of the fax modem driver may cause issues for some users still relying on that functionality, but the security improvements and stability fixes seem to outweigh any potential drawbacks. Microsoft has provided guidance on addressing problems with smart card authentication that may arise from the cryptography changes. While there are always some risks and potential compatibility concerns with any major update, the information provided suggests this is a worthwhile update that should improve the overall reliability and security of affected systems.

Known Issues

• The installation of this Extended Security Update (ESU) might fail when trying to install it on an Azure Arc-enabled device running Windows Server 2012 R2. To successfully install, ensure all Subset of endpoints for ESU only are met as described in the Connected Machine agent network requirements.

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 07:17 PM

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