The Update BureauKB5082413: Cumulative update for .NET Framework, versions 3.5 and 4.7.2, on Windows 10 1809 and Windows Server 2019, April 2026. Critical service-disruption flaw addressed; ClickOnce checks expanded
In short
Six .NET Framework security flaws are addressed, including one critical flaw that could stop a service from responding. ClickOnce also gains support for SHA384 and SHA512 checks.
Does it affect you? Applies to: Devices running Windows 10, version 1809, or Windows Server 2019 with .NET Framework 3.5 or 4.7.2 installed.
Review notes Additional details from the official release notes (1) Read note
- This page The page identifies CVE-2026-32203, CVE-2026-32226, and CVE-2026-23666 as denial-of-service vulnerabilities, but does not identify an affected app or service.
The official sources are linked at the end of the page.
What changes
Fixes 6 changes
.NET Framework
6 items
-
A flaw that could let code run from a remote computer is addressed.1
CVE-2026-32178 is a remote code execution vulnerability.
-
A flaw that could make an app or service stop responding is addressed.2
CVE-2026-32203 is a denial-of-service vulnerability.
-
A flaw that could make an app or service stop responding is addressed.3
CVE-2026-32226 is a denial-of-service vulnerability.
-
A critical flaw that could make a service stop responding is addressed.4
CVE-2026-23666 is a denial-of-service vulnerability.
-
A flaw that could get around a security check is addressed.5
CVE-2026-26171 is a security feature bypass vulnerability.
-
A flaw that could expose information is addressed.6
CVE-2026-33116 is an information disclosure vulnerability.
Improvement 1 change
.NET Runtime
-
ClickOnce apps gain support for SHA384 and SHA512 checks.7
Adds verification logic for ClickOnce to support SHA384 and SHA512.
Technical details
Data sheet · Security · Downloads · Components Click to collapse or expand
Data sheet
- Released
- 2026-04-14
- Classification
- Security Updates
- Type
- Cumulative update
- Restart
- Required
- Replaces
- KB5066143, KB5065744
- Replaced by
- KB5087061
| Version | File version | Channel |
|---|---|---|
| 3.5 | 2.0.50727.9068 | General availability |
| 4.7.2 | 4.7.4141.0 | General availability |
Security
| Vulnerability | Severity | CVSS |
|---|---|---|
|
.NET Framework Denial of Service Vulnerability
|
Critical | 7.5 |
|
.NET, .NET Framework, and Visual Studio Denial of Service Vulnerability
|
Important | 7.5 |
|
.NET Framework Denial of Service Vulnerability
|
Important | 5.9 |
|
.NET Denial of Service Vulnerability
|
Not rated | — |
|
.NET Spoofing Vulnerability
|
Not rated | — |
|
.NET and Visual Studio Denial of Service Vulnerability
|
Not rated | — |
Downloads (Microsoft Update Catalog)
x64
Windows Server 2019 / Windows 10 Enterprise LTSC 2019
83.8 MB
Arm64
Windows 10 Enterprise LTSC 2019
46.8 MB
x86
Windows 10 Enterprise LTSC 2019
46.8 MB
Updated components
51 files changed since the previous update for the same versions.
| Top changed components | Files |
|---|---|
| WCF | 21 |
| Windows Forms | 3 |
Sources
Updated
Cited passages from Microsoft's official notes (7)
-
1.
This security update addresses a remote code execution vulnerability detailed in CVE-2026-32178.
support.microsoft.com -
2.
This security update addresses a denial-of-service vulnerability detailed in CVE-2026-32203.
support.microsoft.com -
3.
This security update addresses a denial-of-service vulnerability detailed in CVE-2026-32226.
support.microsoft.com -
4.
This security update addresses a denial-of-service vulnerability detailed in CVE-2026-23666.
support.microsoft.com -
5.
This security update addresses a security feature bypass vulnerability detailed in CVE-2026-26171.
support.microsoft.com -
6.
This security update addresses an information disclosure vulnerability detailed in CVE-2026-33116.
support.microsoft.com -
7.
Addresses an issue to add verification logic for ClickOnce to support SHA384 and SHA512
support.microsoft.com
Checked automatically: 7 of 8 checks passed, 7 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: not passed
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