CVE-2026-50355: Windows Active Directory Federation Services Denial of Service Vulnerability

Published Jul 14, 2026
·
Updated

Stack-based buffer overflow in Active Directory Federation Services allows an unauthorized attacker to deny service over a network.

Other sources

Windows Active Directory Federation Services Denial of Service Vulnerability

— Microsoft

Affected Software

109 affected componentsFixes available
Microsoft Active Directory Federation Services
Microsoft .NET Framework=3.5
2.0.50727.8983 & 3.0.30729.8978
Microsoft .NET Framework=3.5
2.0.50727.8983 & 3.0.30729.8978
Microsoft .NET Framework=3.5, =4.8.1
2.0.50727.9182 & 3.0.30729.9168 & 4.8.9340.0
Microsoft .NET Framework=3.5, =4.8.1
2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0
Microsoft .NET Framework=3.5, =4.8.1
2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0
Microsoft .NET Framework=3.5, =4.8.1
2.0.50727.9182 & 3.0.30729.9168
Microsoft .NET Framework=3.5, =4.8.1
2.0.50727.9182 & 3.0.30729.9168 & 4.8.9340.0
Microsoft .NET Framework=3.5, =4.8.1
2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0
Microsoft .NET Framework=4.6.2, =4.7, =4.7.1, =4.7.2
4.7.4143.0
Microsoft .NET Framework=4.6.2, =4.7, =4.7.1, =4.7.2
4.7.4143.0
Microsoft .NET Framework=3.5, =4.7.2
2.0.50727.8983 & 3.0.30729.8978 & 4.7.4143.0
Microsoft .NET Framework=3.5, =4.8
2.0.50727.9182 & 3.0.30729.9168 & 4.8.4803.0
Microsoft .NET Framework=3.5, =4.7.2
2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0
Microsoft .NET Framework=3.5, =4.8
2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0
Microsoft .NET Framework=4.8
4.8.4803.0
Microsoft .NET Framework=3.5, =4.8
2.0.50727.9182 & 3.0.30729.9168 & 4.8.4803.0
Microsoft .NET Framework=4.8
4.8.4803.0
Microsoft .NET Framework=4.8
4.8.4803.0
Microsoft .NET Framework=4.8.1
4.8.9340.0
Microsoft Windows 10 1607<10.0.14393.9339
Microsoft Windows 10 1607<10.0.14393.9339
Microsoft Windows 10 1809<10.0.17763.9020
Microsoft Windows 10 1809<10.0.17763.9020
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
Microsoft Windows Server 2016<10.0.14393.9339
Microsoft Windows Server 2019<10.0.17763.9020
Microsoft Windows Server 2022<10.0.20348.5386
Microsoft Windows Server 2025<10.0.26100.33158
All of the following
Microsoft .NET Framework=4.8.1
Any of the following
Microsoft Windows 11 26h1
Microsoft Windows 11 26h1
All of the following
Microsoft .NET Framework=4.8
Any of the following
Microsoft Windows 10 1607
Microsoft Windows 10 1607
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
Microsoft Windows Server 2016
All of the following
Any of the following
Microsoft .NET Framework=4.6.2
Microsoft .NET Framework=4.7
Microsoft .NET Framework=4.7.1
Microsoft .NET Framework=4.7.2
Any of the following
Microsoft Windows Server 2012
Microsoft Windows Server 2012=r2
All of the following
Any of the following
Microsoft .NET Framework=3.5
Microsoft .NET Framework=4.8.1
Any of the following
Microsoft Windows 10 21h2
Microsoft Windows 10 21h2
Microsoft Windows 10 21h2
Microsoft Windows 10 22h2
Microsoft Windows 10 22h2
Microsoft Windows 10 22h2
Microsoft Windows 11 23h2
Microsoft Windows 11 23h2
Microsoft Windows 11 24h2
Microsoft Windows 11 24h2
Microsoft Windows 11 25h2
Microsoft Windows 11 25h2
Microsoft Windows Server 2022
All of the following
Any of the following
Microsoft .NET Framework=3.5
Microsoft .NET Framework=4.8
Any of the following
Microsoft Windows 10 1809
Microsoft Windows 10 1809
Microsoft Windows 10 21h2
Microsoft Windows 10 21h2
Microsoft Windows 10 21h2
Microsoft Windows 10 22h2
Microsoft Windows 10 22h2
Microsoft Windows 10 22h2
Microsoft Windows Server 2019
Microsoft Windows Server 2022
All of the following
Any of the following
Microsoft .NET Framework=3.5
Microsoft .NET Framework=4.7.2
Any of the following
Microsoft Windows 10 1607
Microsoft Windows 10 1607
Microsoft Windows 10 1809
Microsoft Windows 10 1809
Microsoft Windows Server 2016
Microsoft Windows Server 2019
Microsoft Windows Server 2019<10.0.17763.9020
10.0.17763.9020
Microsoft Windows Server 2012 R2<6.3.9600.23291
6.3.9600.23291
Microsoft Windows Server 2016<10.0.14393.9339
10.0.14393.9339
Microsoft Windows Server 2022<10.0.20348.5386
10.0.20348.5386
Microsoft Windows Server 2019<10.0.17763.9020
10.0.17763.9020
Microsoft Windows Server 2025<10.0.26100.33158
10.0.26100.33158
Microsoft Windows Server 2025<10.0.26100.33158
10.0.26100.33158
Microsoft Windows Server 2012<6.2.9200.26226
6.2.9200.26226
Microsoft Windows Server 2012<6.2.9200.26226
6.2.9200.26226
Microsoft Windows Server 2016<10.0.14393.9339
10.0.14393.9339
Microsoft Windows Server 2012 R2<6.3.9600.23291
6.3.9600.23291
Microsoft .NET Framework=3.5, =4.8.1, >=2.0.50727<2.0.50727.9182, >=3.0.30729<3.0.30729.9168
2.0.50727.91823.0.30729.91684.8.9339.0
Microsoft .NET Framework=3.5, =4.8.1, >=2.0.50727<2.0.50727.9182, >=3.0.30729<3.0.30729.9168
2.0.50727.91823.0.30729.91684.8.9339.0
Microsoft .NET Framework=3.5, =4.8.1, >=2.0.50727<2.0.50727.9182, >=3.0.30729<3.0.30729.9168
2.0.50727.91823.0.30729.91684.8.9339.0
Microsoft .NET Framework=3.5, =4.8.1, >=2.0.50727<2.0.50727.9182, >=3.0.30729<3.0.30729.9168
2.0.50727.91823.0.30729.91684.8.9340.0
Microsoft .NET Framework=4.6.2, >=4.7<4.7.4143.0, =4.7.1, =4.7.2
4.7.4143.0
Microsoft .NET Framework=4.6.2, >=4.7<4.7.4143.0, =4.7.1, =4.7.2
4.7.4143.0
Microsoft .NET Framework=3.5, =4.7.2, >=2.0.50727<2.0.50727.8983, >=3.0.30729<3.0.30729.8978
2.0.50727.89833.0.30729.89784.7.4143.0
Microsoft .NET Framework=3.5, =4.7.2, >=2.0.50727<2.0.50727.9069, >=3.0.30729<3.0.30729.9067
2.0.50727.90693.0.30729.90674.7.4143.0
Microsoft .NET Framework=3.5, >=4.8<4.8.4803.0, >=2.0.50727<2.0.50727.9182, >=3.0.30729<3.0.30729.9168
2.0.50727.91823.0.30729.91684.8.4803.0
Microsoft .NET Framework=3.5, >=4.8<4.8.4803.0, >=2.0.50727<2.0.50727.9182, >=3.0.30729<3.0.30729.9168
2.0.50727.91823.0.30729.91684.8.4803.0
Microsoft .NET Framework=3.5, >=4.8<4.8.4803.0, >=2.0.50727<2.0.50727.9069, >=3.0.30729<3.0.30729.9067
2.0.50727.90693.0.30729.90674.8.4803.0
Microsoft .NET Framework>=4.8<4.8.4803.0
4.8.4803.0
Microsoft .NET Framework>=4.8<4.8.4803.0
4.8.4803.0
Microsoft .NET Framework>=4.8<4.8.4803.0
4.8.4803.0
Microsoft Windows 10=1809, >=10.0.17763<10.0.17763.9020
10.0.17763.9020
Microsoft Windows 10=1607, >=10.0.14393<10.0.14393.9339
10.0.14393.9339
Microsoft Windows 10=1607, >=10.0.14393<10.0.14393.9339
10.0.14393.9339
Microsoft Windows 10=1809, >=10.0.17763<10.0.17763.9020
10.0.17763.9020

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.8983 & 3.0.30729.8978Patch KB5100985
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.8983 & 3.0.30729.8978Patch KB5100984
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9340.0Patch KB5101003
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0Patch KB5101001
  5. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9340.0Patch KB5100998
  6. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182 & 3.0.30729.9168Patch KB5101014
  7. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0Patch KB5101004
  8. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0Patch KB5101000
  9. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0Patch KB5101005
  10. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.7.4143.0Patch KB5100991
  11. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.7.4143.0Patch KB5100990
  12. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.8983 & 3.0.30729.8978 & 4.7.4143.0Patch KB5099535
  13. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182 & 3.0.30729.9168 & 4.8.4803.0Patch KB5101006
  14. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0Patch KB5100989
  15. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0Patch KB5101008
  16. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.8.4803.0Patch KB5101011
  17. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182 & 3.0.30729.9168 & 4.8.4803.0Patch KB5101010
  18. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.8.4803.0Patch KB5101007
  19. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.8.4803.0Patch KB5101009
  20. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.8.9340.0Patch KB5101002
  21. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.17763.9020Patch KB5099538
  22. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.3.9600.23291Patch KB5099444
  23. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.14393.9339Patch KB5099535
  24. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.20348.5386Patch KB5099540
  25. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 10.0.26100.33158Patch KB5099536
  26. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.2.9200.26226Patch KB5099445
  27. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182Fixed in 3.0.30729.9168Fixed in 4.8.9339.0Patch KB5101001
  28. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182Fixed in 3.0.30729.9168Fixed in 4.8.9339.0Patch KB5101004
  29. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182Fixed in 3.0.30729.9168Fixed in 4.8.9339.0Patch KB5101000
  30. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182Fixed in 3.0.30729.9168Fixed in 4.8.9340.0Patch KB5100998
  31. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182Fixed in 3.0.30729.9168Fixed in 4.8.9339.0Patch KB5101005
  32. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.8983Fixed in 3.0.30729.8978Fixed in 4.7.4143.0Patch KB5099535
  33. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9069Fixed in 3.0.30729.9067Fixed in 4.7.4143.0Patch KB5100989
  34. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182Fixed in 3.0.30729.9168Fixed in 4.8.4803.0Patch KB5101006
  35. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9182Fixed in 3.0.30729.9168Fixed in 4.8.4803.0Patch KB5101010
  36. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 2.0.50727.9069Fixed in 3.0.30729.9067Fixed in 4.8.4803.0Patch KB5101008

Event History

Jul 14, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeaknessAffected Software
CVE Published
via MITRE·05:06 PM
Data Sourced
via MITRE·05:06 PM
DescriptionSeverity
Data Sourced
via NVD·06:17 PM
RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-50355?

CVE-2026-50355 has a severity rating of 7.5, classified as high.

2

How do I fix CVE-2026-50355?

To mitigate CVE-2026-50355, ensure that your affected Microsoft products are updated to the latest versions provided by Microsoft.

3

What is the impact of CVE-2026-50355?

CVE-2026-50355 can lead to a denial of service, affecting the availability of Active Directory Federation Services.

4

Which software is affected by CVE-2026-50355?

CVE-2026-50355 affects multiple versions of Microsoft Windows and the .NET Framework, including Windows Server 2012 to 2025.

5

Is CVE-2026-50355 a buffer overflow vulnerability?

Yes, CVE-2026-50355 is a stack-based buffer overflow vulnerability.

Company

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