KB5045936: Cumulative update for .NET Framework, versions 3.5 and 4.8, on Windows 10 21H2/22H2, November 2024. Visual Studio compilation error and CLR runtime issues addressed

Addresses a Visual Studio ASP.NET compilation error and several .NET runtime and API issues. It contains no new security improvements.

Does it affect you? Applies to: Devices running Windows 10, version 21H2 or 22H2, with .NET Framework 3.5 or 4.8 installed.

What changes

Verified in package

For: Visual Studio users working with .NET Framework ASP.NET projects

This update addresses an error that can occur during design-time compilation of .NET Framework ASP.NET projects in Visual Studio.¹
The error is: “The type initializer for ‘System.Web.UI.Util’ threw an exception.”

5 items

This update addresses a rare case where a thread entering the CLR for the first time could cause an infinite loop.²
Common Language Runtime (CLR) issue.
This update addresses incorrect interface-call behavior that could occur when JIT optimizations are enabled.³
Addresses incorrect interface call devirtualization when JIT optimizations are enabled.
This update addresses a security feature bypass issue when using SecUtility.RandomByte.⁴
This update addresses an information disclosure issue involving the performance counter.⁵
This update addresses out-of-memory exceptions during garbage collection in applications running under job limits.⁶

For: Applications using the .NET API

This update addresses an issue retrieving a user's group membership through a .NET API.⁷
The affected API is UserPrincipal.GetAuthorizationGroups.

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

Version	File version	Channel
3.5	2.0.50727.9179	General availability
4.8	4.8.4767.0	General availability

No vulnerabilities are listed for this update.

x64 Windows 10 Enterprise LTSC 2021 / Windows 10, version 22H2

76.2 MB

Arm64 Windows 10 Enterprise LTSC 2021 / Windows 10, version 22H2

47.7 MB

x86 Windows 10 Enterprise LTSC 2021 / Windows 10, version 22H2

47.7 MB

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

Top changed components	Files
.NET runtime (CLR)	18
ASP.NET	15

Verified in package: changed files confirm ASP.NET.

Updated Oct 27, 2026

Cited passages from Microsoft's official notes (7)

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. 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. Address an issue in cases where incorrect interface call devirtualization could occur when JIT optimizations are enabled. support.microsoft.com
4. Addresses an issue with a security feature bypass vulnerability when using SecUtility.RandomByte. support.microsoft.com
5. Addresses an issue with information disclosure with the performance counter. support.microsoft.com
6. Addresses an issue with out of memory exceptions during garbage collection while running applications running under job limits. support.microsoft.com
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

A second AI read the text against the sources: correctness 4/5, 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