KB5074831: Cumulative update for .NET Framework, versions 3.5 and 4.8.1, on Windows 11 24H2, January 2026. ClickOnce hash checks added; arm64 runtime crash addressed

Adds ClickOnce verification for SHA384 and SHA512 and addresses an issue that could crash the .NET runtime on arm64 devices.

Does it affect you? Applies to: Devices running Windows 11, version 24H2, or Microsoft server operating system version 24H2, with .NET Framework 3.5 or 4.8.1 installed.

What changes

Fixes 2 changes

.NET Runtime

2 items

ClickOnce verification gains support for SHA384 and SHA512.¹
Addresses an issue by adding verification logic for ClickOnce to support SHA384 and SHA512.
On arm64 devices, the .NET runtime could crash when code generates and catches a null-reference exception in the same function; this update addresses that issue.²
Addresses cases where the arm64 CLR could crash when code generates and catches a NullReferenceException within the same function.

Technical details

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

Data sheet

Released: 2026-01-29
Classification: Updates
Type: Cumulative update
Restart: Required
Replaces: KB5064401, KB5056579, KB5054979, KB5050577

+2 earlier
KB5048162, KB5045934
Replaced by: KB5082420

Version	File version	Channel
3.5	2.0.50727.9180	General availability
4.8.1	4.8.9324.0	General availability

Security

No vulnerabilities are listed for this update.

Downloads (Microsoft Update Catalog)

x64 Windows 11, version 24H2

71.6 MB

windows11.0-kb5074831-x64-ndp481.msu Main update · KB5074831 SHA-1: 485896c1…2b5473

Arm64 Windows 11, version 24H2

88.2 MB

windows11.0-kb5074831-arm64-ndp481.msu Main update · KB5074831 SHA-1: 1d937ee6…46aa39

Updated components

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

Top changed components	Files
.NET runtime (CLR)	12
WCF	12
Windows Forms	2

Sources

Microsoft Support: KB5074831

Updated Oct 26, 2026

Cited passages from Microsoft's official notes (2)

1. Addresses an issue to add verification logic for ClickOnce to support SHA384 and SHA512. support.microsoft.com
2. Addresses an issue in cases where the arm64 CLR could crash when code generates and catches a NullReferenceException within the same function. support.microsoft.com

Checked automatically: 8 of 8 checks passed, 2 quoted passages · compared with Microsoft's page on Sep 25, 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