The Update BureauKB5034468: Cumulative update for .NET Framework, versions 3.5 and 4.8, on Windows 10 21H2/22H2, February 2024. ASP.NET MVC path errors and outdated zlib version addressed
The update addresses an error in some ASP.NET MVC requests and an issue with an outdated zlib library. If you already installed it in the January 23 rollup, no action is needed.
Does it affect you? Applies to: Devices running Windows 10 versions 21H2 or 22H2, including Windows 10 Enterprise LTSC 2021, with .NET Framework 3.5 or 4.8 installed.
What changes
Fixes 2 changes
ASP.NET
For: Applications using ASP.NET MVC
-
The update addresses an error that can occur in some ASP.NET MVC requests with illegal characters in the path.1
The error is
System.ArgumentException: Illegal characters in path.
.NET Libraries
For: Applications using .NET libraries
- The update addresses an issue with an outdated version of the open-source zlib library.2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
- KB5036608
| Version | File version | Channel |
|---|---|---|
| 3.5 | 2.0.50727.9176 | General availability |
| 4.8 | 4.8.4697.0 | General availability |
Security
No vulnerabilities are listed for this update.
Downloads (Microsoft Update Catalog)
Updated components
78 files changed since the previous update for the same versions.
| Top changed components | Files |
|---|---|
| WPF | 33 |
| ASP.NET | 15 |
Verified in package: changed files confirm ASP.NET.
Sources
Cited passages from Microsoft's official notes (2)
-
1.
Addresses an issue with "System.ArgumentException: Illegal characters in path" in some ASP.Net MVC requests.
support.microsoft.com -
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Addresses an issue where version of the OSS zlib library is out of date.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