KB5126145: Overview with user sentiment and feedback
Last Updated October 28, 2026
Probability of successful installation and continued operation of the machine
Overview
KB5126145 is the September 8, 2026 cumulative update for .NET Framework 3.5, 4.8 and 4.8.1 on Windows 10 Version 21H2. It is a security and quality rollup delivered through Windows Update, WSUS (Security Updates classification) and the Microsoft Update Catalog. It is intended for Windows 10 21H2 systems running those .NET Framework versions.
General Purpose
- Fixes CVE-2026-62886, a .NET Framework elevation of privilege vulnerability.
- Fixes CVE-2026-69522, a .NET Framework remote code execution vulnerability.
- Includes additional quality and reliability improvements, detailed in linked KB5126046 (3.5/4.8) and KB5126421 (4.8.1) articles.
- Installs automatically via Windows Update; standalone package available from the Update Catalog.
General Sentiment
Community discussion was not available in the provided data, so no user reports could be reviewed. Microsoft's documentation lists no known issues, and the update's security fixes are a reason to deploy promptly.
Known Issues
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 2026-10-28 02:10 PM
