Skip to the content
The Update Bureau
.NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 Security update
Patch Tuesday

KB5120714

KB5120714: Cumulative update for .NET Framework, versions 3.5 and 4.8.1, on Windows Server 2022, August 2026. Six runtime vulnerabilities addressed; WPF printing may fail

In short

Addresses six .NET Framework vulnerabilities, including remote-code-execution flaws. Some WPF apps may fail when printing or generating PDF/XPS content; later cumulative updates resolve the two listed issues.

Does it affect you? Applies to: Windows Server 2022 devices with .NET Framework 3.5 or 4.8.1 installed.

File version
2.0.50727.9183 · 4.8.9343.0
Security
6 fixed
Restart
Required

What changes

Fixes 6 changes

.NET Framework

6 items
  • A .NET Framework elevation-of-privilege vulnerability is addressed.1
    CVE-2026-65810.
  • A .NET Framework elevation-of-privilege vulnerability is addressed.2
    CVE-2026-62872.
  • A .NET Framework remote-code-execution vulnerability is addressed.3
    CVE-2026-62886.
  • A .NET Framework remote-code-execution vulnerability is addressed.4
    CVE-2026-62897.
  • A .NET Framework remote-code-execution vulnerability is addressed.5
    CVE-2026-70354.
  • A .NET Framework information-disclosure vulnerability is addressed.6
    CVE-2026-62902.

Known issues

  1. Resolved Affects: Everyone

    After installing the August 2026 .NET Framework cumulative update, some WPF applications may fail with a System.IO.File…

    Some WPF apps may fail with a System.IO.FileFormatException when printing or generating PDF/XPS content that uses certain fonts, including Calibri. The September 2026 .NET Framework cumulative update and later updates resolve this issue.7

    How to apply the workaround Workaround

    As a temporary measure, enable Switch.MS.Internal.TtfDelta.DisableCmapAndSbitOverflowProtection in the app config only when required.7

  2. Resolved Affects: Everyone

    After installing the August 2026 .NET Framework cumulative update, WPF applications that print—or display print preview…

    WPF apps that print or show print preview from certain in-memory XPS documents may fail with a System.IO.FileFormatException while loading. The October 2026 .NET Framework cumulative update and later updates resolve this issue.8

    How to apply the workaround Workaround

    If the app can be rebuilt, use an absolute package identity that does not use the pack scheme. If it cannot be rebuilt, temporarily enable Switch.System.Windows.DisableXpsPackageBoundaryRestriction in the app config when required.8

    Step-by-step workaround instructions
    2 steps
    Show steps Hide steps
    Step-by-step procedure
    1. If the app can be rebuilt, use an absolute package identity such as xpspack://<guid>.xps instead of one using the pack scheme.
    2. If the app cannot be rebuilt, add Switch.System.Windows.DisableXpsPackageBoundaryRestriction to the application configuration file as a temporary measure.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released
2026-08-11
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5101005, KB5087059
Replaced by
KB5126422
VersionFile versionChannel
3.5 2.0.50727.9183 General availability
4.8.1 4.8.9343.0 General availability

Security

6 vulnerabilities fixed
4 important 2 not rated
VulnerabilitySeverityCVSS
CVE-2026-62872
.NET Framework Elevation of Privilege Vulnerability
 Important 8.8
CVE-2026-65810
.NET Framework Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-70354
.NET Core Remote Code Execution Vulnerability
 Important 7.8
CVE-2026-62897
.NET Framework Remote Code Execution Vulnerability
 Important 7.0
CVE-2026-62886
.NET Elevation of Privilege Vulnerability
 Not rated —
CVE-2026-62902
.NET Information Disclosure Vulnerability
 Not rated —

Downloads (Microsoft Update Catalog)

x64 Windows Server 2022
76.2 MB
windows10.0-kb5120714-x64-ndp481.msu Main update · KB5120714 SHA-1: 3a009ef9…a8d861

Updated components

79 files changed since the previous update for the same versions.

Top changed componentsFiles
WPF28
ASP.NET12
.NET runtime (CLR)4

Page history

  1. Added CVE-2026-62897 (Important)

Sources

Updated
Cited passages from Microsoft's official notes (8)
  1. 1. This security update addresses an elevation of privilege vulnerability detailed in CVE-2026-65810. support.microsoft.com
  2. 2. This security update addresses an elevation of privilege vulnerability detailed in CVE-2026-62872. support.microsoft.com
  3. 3. This security update addresses a remote code execution vulnerability detailed in CVE-2026-62886. support.microsoft.com
  4. 4. This security update addresses a remote code execution vulnerability detailed in CVE-2026-62897. support.microsoft.com
  5. 5. This security update addresses a remote code execution vulnerability detailed in CVE-2026-70354. support.microsoft.com
  6. 6. This security update addresses an information disclosure vulnerability detailed in CVE-2026-62902. support.microsoft.com
  7. 7. This issue is resolved in the September 2026 .NET Framework cumulative update and later updates. support.microsoft.com
  8. 8. This issue is resolved in the October 2026 .NET Framework cumulative update and later updates. support.microsoft.com
Checked automatically: 7 of 8 checks passed, 8 quoted passages · compared with Microsoft's page on Oct 16, 2026
  • Quotes found in the official pages: passed
  • Numbers found in the sources: passed
  • Vulnerabilities from the dossier only: passed
  • Links to allowed domains only: passed
  • Every official change covered: passed
  • Readable plain text: passed
  • Changes confirmed by the file list: passed
  • Sources agree: not passed

A second AI read the text against the sources: correctness 5/5, clarity 4/5, completeness 5/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake