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.NET Framework 3.5 / 4.7.2 .NET Framework 3.5 / 4.7.2 Security update
Patch Tuesday

KB5100989

KB5100989: Cumulative update for .NET Framework, versions 3.5 and 4.7.2, on Windows 10 1809 and Windows Server 2019, July 2026. Secure web request hangs addressed; 17 security flaws fixed

In short

Fixes 17 Important .NET Framework security flaws and a problem that could leave some secure web requests stuck. A restart may be needed if affected files are in use.

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.

File version
2.0.50727.9069 · 4.7.4143.0
Security
17 fixed
Restart
Required

What changes

Fixes 18 changes

.NET Framework

17 items

For: devices with .NET Framework

  • A flaw that could make a .NET app stop responding is fixed.1
    CVE-2026-47302: denial of service vulnerability.
  • A flaw that could bypass a security feature is fixed.2
    CVE-2026-47304: security feature bypass vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.3
    CVE-2026-50304: denial of service vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.4
    CVE-2026-50324: denial of service vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.5
    CVE-2026-50355: denial of service vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.6
    CVE-2026-50368: denial of service vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.7
    CVE-2026-50411: denial of service vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.8
    CVE-2026-50525: denial of service vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.9
    CVE-2026-50527: denial of service vulnerability.
  • A flaw that could let a user gain more access is fixed.10
    CVE-2026-50646: elevation of privilege vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.11
    CVE-2026-50647: denial of service vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.12
    CVE-2026-50648: denial of service vulnerability.
  • A flaw that could let code run remotely is fixed.13
    CVE-2026-50649: remote code execution vulnerability.
  • A flaw that could let a user gain more access is fixed.14
    CVE-2026-50650: elevation of privilege vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.15
    CVE-2026-50652: denial of service vulnerability.
  • A flaw that could make a .NET app stop responding is fixed.16
    CVE-2026-50653: denial of service vulnerability.
  • A flaw that could let data be changed is fixed.17
    CVE-2026-50659: tampering vulnerability.

.NET Libraries

  • Some secure web requests could get stuck. This update addresses the problem with certain server setups.18
    Addresses an issue with synchronous HttpWebRequest connections in specific secure connection scenarios with certain server configurations.

Technical details

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

Data sheet

Released
2026-07-14
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5087061, KB5082413
Replaced by
KB5120698
VersionFile versionChannel
3.5 2.0.50727.9069 General availability
4.7.2 4.7.4143.0 General availability

Security

17 vulnerabilities fixed
17 important
VulnerabilitySeverityCVSS
CVE-2026-47304
.NET Security Feature Bypass Vulnerability
 Important 8.1
CVE-2026-50646
.NET Framework Remote Code Execution Vulnerability
 Important 7.8
CVE-2026-50649
.NET Remote Code Execution Vulnerability
 Important 7.8
CVE-2026-50650
.NET Framework Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-47302
.NET Denial of Service Vulnerability
 Important 7.5
CVE-2026-50304
Windows Active Directory Federation Services Denial of Service Vulnerability
 Important 7.5
CVE-2026-50355
Windows Active Directory Federation Services Denial of Service Vulnerability
 Important 7.5
CVE-2026-50368
Windows Active Directory Federation Services Denial of Service Vulnerability
 Important 7.5
CVE-2026-50411
Windows Active Directory Federation Services Denial of Service Vulnerability
 Important 7.5
CVE-2026-50525
.NET Denial of Service Vulnerability
 Important 7.5
CVE-2026-50527
.NET Framework Denial of Service Vulnerability
 Important 7.5
CVE-2026-50647
Active Directory Federation Server Denial of Service Vulnerability
 Important 7.5
CVE-2026-50648
.NET Framework Denial of Service Vulnerability
 Important 7.5
CVE-2026-50652
Azure Active Directory Denial of Service Vulnerability
 Important 7.5
CVE-2026-50653
Azure Active Directory Denial of Service Vulnerability
 Important 7.5
CVE-2026-50659
.NET Spoofing Vulnerability
 Important 6.5
CVE-2026-50324
Windows Active Directory Federation Services Denial of Service Vulnerability
 Important 5.9

Downloads (Microsoft Update Catalog)

x64 Windows Server 2019 / Windows 10 Enterprise LTSC 2019
87.1 MB
windows10.0-kb5100989-x64.msu Main update · KB5100989 SHA-1: a11d5744…e40e07
Arm64 Windows 10 Enterprise LTSC 2019
49.1 MB
windows10.0-kb5100989-arm64.msu Main update · KB5100989 SHA-1: 959469c6…073bd1
x86 Windows 10 Enterprise LTSC 2019
49.1 MB
windows10.0-kb5100989-x86.msu Main update · KB5100989 SHA-1: f5925686…f90e01

Updated components

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

Top changed componentsFiles
WPF42
WCF21
.NET networking9
.NET data access3

Sources

Updated
Cited passages from Microsoft's official notes (18)
  1. 1. This security update addresses a denial of service vulnerability detailed in CVE-2026-47302. support.microsoft.com
  2. 2. This security update addresses a security feature bypass vulnerability detailed in CVE-2026-47304. support.microsoft.com
  3. 3. This security update addresses a denial of service vulnerability detailed in CVE-2026-50304. support.microsoft.com
  4. 4. This security update addresses a denial of service vulnerability detailed in CVE-2026-50324. support.microsoft.com
  5. 5. This security update addresses a denial of service vulnerability detailed in CVE-2026-50355. support.microsoft.com
  6. 6. This security update addresses a denial of service vulnerability detailed in CVE-2026-50368. support.microsoft.com
  7. 7. This security update addresses a denial of service vulnerability detailed in CVE-2026-50411. support.microsoft.com
  8. 8. This security update addresses a denial of service vulnerability detailed in CVE-2026-50525. support.microsoft.com
  9. 9. This security update addresses a denial of service vulnerability detailed in CVE-2026-50527. support.microsoft.com
  10. 10. This security update addresses an elevation of privilege vulnerability detailed in CVE-2026-50646. support.microsoft.com
  11. 11. This security update addresses a denial of service vulnerability detailed in CVE-2026-50647. support.microsoft.com
  12. 12. This security update addresses a denial of service vulnerability detailed in CVE-2026-50648. support.microsoft.com
  13. 13. This security update addresses a remote code execution vulnerability detailed in CVE-2026-50649. support.microsoft.com
  14. 14. This security update addresses an elevation of privilege vulnerability detailed in CVE-2026-50650. support.microsoft.com
  15. 15. This security update addresses a denial of service vulnerability detailed in CVE-2026-50652. support.microsoft.com
  16. 16. This security update addresses a denial of service vulnerability detailed in CVE-2026-50653. support.microsoft.com
  17. 17. This security update addresses a tampering vulnerability detailed in CVE-2026-50659. support.microsoft.com
  18. 18. Addresses an issue with synchronous HttpWebRequest connections where requests could hang in specific secure connection scenarios with certain server configurations. support.microsoft.com
Checked automatically: 8 of 8 checks passed, 18 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 5/5, 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