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.NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 Security update
Patch Tuesday

KB5127690

KB5127690

Cumulative update for .NET Framework, versions 3.5 and 4.8.1, on Windows 11 24H2/25H2 and Windows Server 2025, October 2026

In short

Addresses a critical spoofing flaw and other security risks in .NET Framework. It covers 21 vulnerabilities, including one that was publicly disclosed.

Does it affect you? Applies to: Devices running Windows 11, version 24H2 or 25H2, or Windows Server 2025, with .NET Framework 3.5 or 4.8.1 installed.

File version
2.0.50727.9188 · 4.8.9363.0
Security
21 fixed · 1 critical
Restart
Required

What changes

Fixes 19 changes

.NET Framework

19 items
  • Helps prevent denial-of-service attacks on .NET Framework.1
    CVE-2026-58280 is a denial-of-service vulnerability.
  • Helps stop attackers from gaining higher access through .NET Framework.2
    CVE-2026-69439 is an elevation-of-privilege vulnerability.
  • Helps prevent denial-of-service attacks on .NET Framework.3
    CVE-2026-69651 is a denial-of-service vulnerability.
  • Helps stop attackers from running code through .NET Framework.4
    CVE-2026-70007 is a remote-code-execution vulnerability.
  • Helps stop attackers from running code through .NET Framework.5
    CVE-2026-70035 is a remote-code-execution vulnerability.
  • Helps stop attackers from running code through .NET Framework.6
    CVE-2026-70174 is a remote-code-execution vulnerability.
  • Helps stop attackers from running code through .NET Framework.7
    CVE-2026-83520 is a remote-code-execution vulnerability.
  • Helps prevent denial-of-service attacks on .NET Framework.8
    CVE-2026-84008 is a denial-of-service vulnerability.
  • Helps stop attackers from gaining higher access through .NET Framework.9
    CVE-2026-85363 is an elevation-of-privilege vulnerability.
  • Helps stop attackers from running code through .NET Framework.10
    CVE-2026-87697 is a remote-code-execution vulnerability.
  • Helps stop attackers from pretending to be someone else through .NET Framework.11
    CVE-2026-96222 is a spoofing vulnerability.
  • Helps stop attackers from running code through .NET Framework.12
    CVE-2026-96224 is a remote-code-execution vulnerability.
  • Helps prevent denial-of-service attacks on .NET Framework.13
    CVE-2026-96233 is a denial-of-service vulnerability.
  • Helps prevent denial-of-service attacks on .NET Framework.14
    CVE-2026-96958 is a denial-of-service vulnerability.
  • Helps prevent denial-of-service attacks on .NET Framework.15
    CVE-2026-96959 is a denial-of-service vulnerability.
  • Helps prevent denial-of-service attacks on .NET Framework.16
    CVE-2026-96960 is a denial-of-service vulnerability.
  • Helps stop attackers from seeing information they should not see.17
    CVE-2026-97788 is an information-disclosure vulnerability.
  • Helps stop attackers from making unauthorized changes through .NET Framework.18
    CVE-2026-97801 is a tampering vulnerability.
  • Helps stop attackers from bypassing a .NET Framework security feature.19
    CVE-2026-108398 is a security feature bypass vulnerability.

Technical details

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

Data sheet

Released
2026-10-13
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5126052, KB5122385, KB5120708, KB5120710
+22 earlier KB5100998, KB5101001, KB5092427, KB5092430, KB5087051, KB5087054, KB5082417, KB5082420, KB5074831, KB5074828, KB5067931, KB5066128, KB5066131, KB5066613, KB5064401, KB5056579, KB5054979, KB5050577, KB5049622, KB5048162, KB5045934, KB5044030
VersionFile versionChannel
3.5 2.0.50727.9188 General availability
4.8.1 4.8.9363.0 General availability

Security

21 vulnerabilities fixed
1 critical 18 important 2 not rated
VulnerabilitySeverityCVSS
CVE-2026-96222
Active Directory Federation Services (AD FS) Spoofing Vulnerability
 Critical 7.4
CVE-2026-102869
.NET and Visual Studio Elevation of Privilege Vulnerability
 Important 8.8
CVE-2026-108398
.NET Framework Security Feature Bypass Vulnerability
 Important 8.8
CVE-2026-70007
.NET Framework Remote Code Execution Vulnerability
 Important 8.8
CVE-2026-70035
.NET Framework Remote Code Execution Vulnerability
 Important 8.8
CVE-2026-70174
.NET Remote Code Execution Vulnerability
 Important 8.8
CVE-2026-83520
.NET Remote Code Execution Vulnerability
 Important 8.8
CVE-2026-85363
.NET Framework Elevation of Privilege Vulnerability
 Important 8.8
CVE-2026-96224
.NET Remote Code Execution Vulnerability
 Important 8.8
CVE-2026-62886
.NET Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-58280
.NET Denial of Service Vulnerability
 Important 7.5
CVE-2026-69651
.NET Denial of Service Vulnerability
 Important 7.5
CVE-2026-84008
.NET Denial of Service Vulnerability
 Important 7.5
CVE-2026-96233
ASP.NET Core Denial of Service Vulnerability
 Important 7.5
CVE-2026-96958
.NET Denial of Service Vulnerability
 Important 7.5
CVE-2026-96959
.NET Denial of Service Vulnerability
 Important 7.5
CVE-2026-96960
.NET Denial of Service Vulnerability
 Important 7.5
CVE-2026-97788
Active Directory Federation Services (AD FS) Information Disclosure Vulnerability
 Important 7.5
CVE-2026-97801
.NET Framework Tampering Vulnerability
 Important 7.5
CVE-2026-69439
.NET and Visual Studio Elevation of Privilege Vulnerability
 Not rated —
CVE-2026-87697
.NET Remote Code Execution Vulnerability
 Not rated —

Downloads (Microsoft Update Catalog)

x64 Windows 11, version 24H2 / Windows Server 2025 / Windows 11, version 25H2
92.3 MB
windows11.0-kb5127690-x64-ndp481.msu Main update · KB5127690 SHA-1: 2799c972…38ed95
Arm64 Windows 11, version 24H2 / Windows Server 2025 / Windows 11, version 25H2
110.6 MB
windows11.0-kb5127690-arm64-ndp481.msu Main update · KB5127690 SHA-1: dc35585d…cc45b7

Updated components

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

Top changed componentsFiles
WPF32
WCF21
.NET runtime (CLR)14
ASP.NET3
.NET data access2
Windows Forms2

Sources

Updated
Cited passages from Microsoft's official notes (19)
  1. 1. This security update addresses a denial of service vulnerability detailed in CVE-2026-58280. support.microsoft.com
  2. 2. This security update addresses an elevation of privilege vulnerability detailed in CVE-2026-69439. support.microsoft.com
  3. 3. This security update addresses a denial of service vulnerability detailed in CVE-2026-69651. support.microsoft.com
  4. 4. This security update addresses a remote code execution vulnerability detailed in CVE-2026-70007. support.microsoft.com
  5. 5. This security update addresses a remote code execution vulnerability detailed in CVE-2026-70035. support.microsoft.com
  6. 6. This security update addresses a remote code execution vulnerability detailed in CVE-2026-70174. support.microsoft.com
  7. 7. This security update addresses a remote code execution vulnerability detailed in CVE-2026-83520. support.microsoft.com
  8. 8. This security update addresses a denial of service vulnerability detailed in CVE-2026-84008. support.microsoft.com
  9. 9. This security update addresses an elevation of privilege vulnerability detailed in CVE-2026-85363. support.microsoft.com
  10. 10. This security update addresses a remote code execution vulnerability detailed in CVE-2026-87697. support.microsoft.com
  11. 11. This security update addresses a spoofing vulnerability detailed in CVE-2026-96222. support.microsoft.com
  12. 12. This security update addresses a remote code execution vulnerability detailed in CVE-2026-96224. support.microsoft.com
  13. 13. This security update addresses a denial of service vulnerability detailed in CVE-2026-96233. support.microsoft.com
  14. 14. This security update addresses a denial of service vulnerability detailed in CVE-2026-96958. support.microsoft.com
  15. 15. This security update addresses a denial of service vulnerability detailed in CVE-2026-96959. support.microsoft.com
  16. 16. This security update addresses a denial of service vulnerability detailed in CVE-2026-96960. support.microsoft.com
  17. 17. This security update addresses an information disclosure vulnerability detailed in CVE-2026-97788. support.microsoft.com
  18. 18. This security update addresses a tampering vulnerability detailed in CVE-2026-97801. support.microsoft.com
  19. 19. This security update addresses a security feature bypass vulnerability detailed in CVE-2026-108398. support.microsoft.com
Checked automatically: 7 of 8 checks passed, 19 quoted passages · compared with Microsoft's page on Nov 14, 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 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