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

KB5046269

KB5046269: Cumulative update for .NET Framework, versions 3.5 and 4.8, on Windows 10 1809 and Windows Server 2019, November 2024. SecUtility bypass and performance-counter disclosure addressed

In short

Addresses several .NET reliability problems, including a security feature-bypass issue and performance-counter information disclosure. It also addresses ASP.NET compilation, runtime, and user-group lookup problems.

Does it affect you? Applies to: Devices running Windows 10, version 1809, or Windows Server 2019 with .NET Framework 3.5 or 4.8 installed.

File version
2.0.50727.9066 · 4.8.4770.0
Restart
Required

What changes

Fixes 7 changes

ASP.NET

Verified in package

For: Developers using ASP.NET projects in Visual Studio

  • The System.Web.UI.Util initializer error during Visual Studio design-time compilation is addressed.1
    The issue occurs during design-time compilation in Visual Studio for .NET Framework ASP.NET projects.

CLR

5 items
  • In rare cases, a thread could get stuck in an endless loop the first time it entered the .NET runtime; this issue is addressed.2
    The issue could occur when a thread enters the Common Language Runtime (CLR) for the first time.
  • When .NET optimizations are enabled, an interface call could be handled incorrectly; this issue is addressed.3
    Incorrect interface-call devirtualization could occur when JIT optimizations are enabled.
  • A security feature could be bypassed when SecUtility.RandomByte is used; this issue is addressed.4
  • A performance counter could disclose information; this issue is addressed.5
  • Apps running with resource limits could run out of memory while .NET cleans up unused objects; this issue is addressed.6
    The issue involved out-of-memory exceptions during garbage collection in applications running under job limits.

.NET Fundamentals

For: .NET application developers

  • An issue retrieving a user's group memberships through .NET is addressed.7
    The issue affects .NET API UserPrincipal.GetAuthorizationGroups when retrieving a user's membership.

Technical details

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

Data sheet

Released
2024-11-12
Classification
Updates
Type
Cumulative update
Restart
Required
Replaces
KB5041974
Replaced by
KB5049615
VersionFile versionChannel
3.5 2.0.50727.9066 General availability
4.8 4.8.4770.0 General availability

Security

No vulnerabilities are listed for this update.

Downloads (Microsoft Update Catalog)

x64 Windows Server 2019 / Windows 10 Enterprise LTSC 2019
88.9 MB
windows10.0-kb5046269-x64-ndp48.msu Main update · KB5046269 SHA-1: ffaedfbf…53b2f6
x86 Windows 10 Enterprise LTSC 2019
49.9 MB
windows10.0-kb5046269-x86-ndp48.msu Main update · KB5046269 SHA-1: 6da60a7d…816442

Updated components

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

Top changed componentsFiles
.NET runtime (CLR)12
ASP.NET10

Verified in package: changed files confirm ASP.NET.

Sources

Updated
Cited passages from Microsoft's official notes (7)
  1. 1. Addresses an issue where "The type initializer for ‘System.Web.UI.Util’ threw an exception." error with design-time compilation in Visual Studio for .NET Framework ASP.Net projects. support.microsoft.com
  2. 2. Address an issue where in rare cases where an infinite loop could occur when a thread enters CLR for the first time. support.microsoft.com
  3. 3. Address an issue in cases where incorrect interface call devirtualization could occur when JIT optimizations are enabled. support.microsoft.com
  4. 4. Addresses an issue with a security feature bypass vulnerability when using SecUtility.RandomByte. support.microsoft.com
  5. 5. Addresses an issue with information disclosure with the performance counter. support.microsoft.com
  6. 6. Addresses an issue with out of memory exceptions during garbage collection while running applications running under job limits. support.microsoft.com
  7. 7. Addresses an issue with .NET API UserPrincipal.GetAuthorizationGroups to retrieve the Membership of a particular user. support.microsoft.com
Checked automatically: 8 of 8 checks passed, 7 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