Home/KB Catalog/KB5120710

KB5120710: Overview with user sentiment and feedback

Last Updated September 30, 2026

Probability of successful installation and continued operation of the machine

0%
20%
40%
60%
80%
100%
60%
Known Issues

Overview

Released on August 11, 2026, KB5120710 is a cumulative security and reliability update for .NET Framework 3.5 and 4.8.1 targeting Windows 11 version 24H2. This patch addresses six critical security vulnerabilities including multiple remote code execution and elevation of privilege issues. The update is recommended for regular maintenance routines and requires .NET Framework 3.5 or 4.8.1 to be pre-installed.

General Purpose

  • Addresses six critical security vulnerabilities (CVE-2026-65810, CVE-2026-62872, CVE-2026-62886, CVE-2026-62897, CVE-2026-70354, CVE-2026-62902)
  • Resolves two elevation of privilege vulnerabilities in .NET Framework
  • Resolves three remote code execution vulnerabilities affecting .NET Framework
  • Resolves one information disclosure vulnerability
  • Includes cumulative reliability improvements for .NET Framework 3.5 and 4.8.1

General Sentiment

This is a security-focused cumulative update with significant vulnerability remediation. While the patch addresses critical security issues that warrant installation, it introduces two confirmed known issues affecting WPF applications during printing and PDF/XPS generation operations. Microsoft has provided workarounds for both issues, though these workarounds require disabling some security protections. The September 2026 update reportedly resolves the primary issue, suggesting Microsoft is actively addressing the problems introduced by this patch.

Known Issues

  • WPF applications may fail with System.IO.FileFormatException when printing or generating PDF/XPS content using certain fonts including Calibri; resolved in September 2026 update
  • WPF applications printing or displaying print preview from in-memory XPS documents registered with System.IO.Packaging.PackageStore may fail with System.IO.FileFormatException; status is under investigation

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 2026-09-30 07:34 AM

Back to Knowledge Base Catalog