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.NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 Update
Patch Tuesday

KB5042097

KB5042097: Cumulative update for .NET Framework, versions 3.5 and 4.8.1, on Windows 10 21H2/22H2, August 2024. ASP.NET compilation conflicts and UI automation rendering addressed

In short

Addresses .NET Framework reliability issues, including UI automation rendering and compilation conflicts that could slow work on large projects.

Does it affect you? Applies to: Devices running Windows 10, version 21H2 or 22H2, with .NET Framework 3.5 or 4.8.1 installed.

File version
2.0.50727.9179 · 4.8.9261.0
Restart
Required

What changes

Fixes 5 changes

.NET Libraries

  • The update addresses an issue with bringing the zlib file up to its latest version.1

.NET Fundamentals

Verified in package 4 items

For: developers

  • The update addresses a problem rendering ListView subitems used by UI automation.2
  • The update addresses an issue involving a serialization binder bypass through BinaryFormatter mutations.3
  • ASP.NET WebForms SmartNavigation no longer includes meta-tag information referencing the Recreational Software Advisory Council or the content-rating schema.4
  • The update addresses compilation conflicts in some .NET Framework ASP.NET projects; these conflicts could slow the developer experience on large projects.5
    The conflicts involve design-time and debug/runtime compilation when .NET Framework interacts with Visual Studio.

Technical details

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

Data sheet

Released
2024-08-13
Classification
Updates
Type
Cumulative update
Restart
Required
Replaces
KB5037587
Replaced by
KB5044029
VersionFile versionChannel
3.5 2.0.50727.9179 General availability
4.8.1 4.8.9261.0 General availability

Security

No vulnerabilities are listed for this update.

Downloads (Microsoft Update Catalog)

x64 Windows 10 Enterprise LTSC 2021 / Windows 10, version 22H2
75.2 MB
windows10.0-kb5042097-x64-ndp481.msu Main update · KB5042097 SHA-1: 128df6c4…3329a3
x86 Windows 10 Enterprise LTSC 2021 / Windows 10, version 22H2
46.6 MB
windows10.0-kb5042097-x86-ndp481.msu Main update · KB5042097 SHA-1: 0a1a1df0…e586c7

Updated components

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

Top changed componentsFiles
WPF33
.NET runtime (CLR)21
ASP.NET15

Verified in package: changed files confirm .NET Fundamentals.

Sources

Updated
Cited passages from Microsoft's official notes (5)
  1. 1. Addresses an issue to update zlib file to latest version. support.microsoft.com
  2. 2. Addresses an issue to render UI automation ListView sub items. support.microsoft.com
  3. 3. Addresses an issue with bypass serialization binder with binary formatter mutations. support.microsoft.com
  4. 4. Addresses an issue to remove meta tag information referencing "Recreational Software Advisory Council" and the content-rating schema from ASP.Net WebForms SmartNavigation feature. support.microsoft.com
  5. 5. to avoid conflicts between design-time and debug/runtime compilation of some .NET Framework ASP.NET project that could result in slowed developer experience for large projects. support.microsoft.com
Checked automatically: 8 of 8 checks passed, 5 quoted passages · compared with Microsoft's page on Oct 20, 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: passed

A second AI read the text against the sources: correctness 5/5, clarity 3/5, 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