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.NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 Update
Patch Tuesday

KB5034613

KB5034613: Cumulative update for .NET Framework, versions 3.5 and 4.8, on Windows Server 2022, February 2024. ASP.NET MVC path errors and an outdated zlib library addressed

In short

The update addresses an “Illegal characters in path” error in some ASP.NET MVC requests and an outdated version of the OSS zlib library.

Does it affect you? Applies to: Devices running Windows Server 2022 with .NET Framework 3.5 or 4.8 installed.

File version
2.0.50727.9176 · 4.8.4700.0
Restart
Required

What changes

Fixes 2 changes

ASP.NET

Verified in package

For: ASP.NET MVC applications

  • The update addresses an “Illegal characters in path” error in some ASP.NET MVC requests.1
    The issue involves System.ArgumentException: Illegal characters in path.

.NET Libraries

For: .NET applications

  • The update addresses an outdated version of the OSS zlib library.2

Technical details

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

Data sheet

Released
2024-02-13
Classification
Updates
Type
Cumulative update
Restart
Required
Replaced by
KB5036613
VersionFile versionChannel
3.5 2.0.50727.9176 General availability
4.8 4.8.4700.0 General availability

Security

No vulnerabilities are listed for this update.

Downloads (Microsoft Update Catalog)

x64 Windows Server 2022
66.1 MB
windows10.0-kb5034613-x64-ndp48.msu Main update · KB5034613 SHA-1: 466f9e69…6adb1c

Updated components

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

Top changed componentsFiles
WPF22
ASP.NET10

Verified in package: changed files confirm ASP.NET.

Sources

Updated
Cited passages from Microsoft's official notes (2)
  1. 1. Addresses an issue with "System.ArgumentException: Illegal characters in path" in some ASP.Net MVC requests. support.microsoft.com
  2. 2. Addresses an issue where version of the OSS zlib library is out of date. support.microsoft.com
Checked automatically: 8 of 8 checks passed, 2 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 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