CVE-2026-96959: .NET Denial of Service Vulnerability

Overview

Severity

High (CVSS 7.5)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C

Category

Denial of Service

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Oct

Released

2026-10-13

Description

Allocation of resources without limits or throttling in .NET allows an unauthorized attacker to deny service over a network.

Affected Products (39)

Other

• System.Security.Cryptography.Xml on .NET 10.0 installed on Windows
• System.Security.Cryptography.Xml on .NET 10.0 installed on Linux
• System.Security.Cryptography.Xml on .NET 10.0 installed on Mac OS
• System.Security.Cryptography.Xml on .NET 11.0 installed on Windows
• System.Security.Cryptography.Xml on .NET 11.0 installed on Linux
• System.Security.Cryptography.Xml on .NET 11.0 installed on Mac OS
• System.Security.Cryptography.Xml on .NET 8.0 installed on Windows
• System.Security.Cryptography.Xml on .NET 8.0 installed on Linux
• System.Security.Cryptography.Xml on .NET 8.0 installed on Mac OS
• System.Security.Cryptography.Xml on .NET 9.0 installed on Windows
• System.Security.Cryptography.Xml on .NET 9.0 installed on Linux
• System.Security.Cryptography.Xml on .NET 9.0 installed on Mac OS

Developer Tools

• Microsoft .NET Framework 3.5 on Windows 11 version 26H1
• Microsoft .NET Framework 3.5 on Windows Server 2012
• Microsoft .NET Framework 3.5 on Windows Server 2012 R2
• Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows 10 version 1607
• Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016
• Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2019
• Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 version 1809
• Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 1809
• Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 21H2
• Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 22H2
• Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019
• Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022
• Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012
• Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2
• Microsoft .NET Framework 4.8 on Windows 10 version 1607
• Microsoft .NET Framework 4.8 on Windows Server 2012
• Microsoft .NET Framework 4.8 on Windows Server 2012 R2
• Microsoft .NET Framework 4.8 on Windows Server 2016
• Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 version 21H2
• Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 version 22H2
• Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 24H2
• Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 25H2
• Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2025
• Microsoft .NET Framework 4.8.1 on Windows 11 version 26H1
• Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 23H2
• Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2022
• Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 26H2

Security Updates (20)

• Release Notes
• 5127696
• 5127660
• 5127664
• 5126868
• 5127666
• 5127685
• 5127683
• 5127687
• 5127667
• 5127668
• 5127684
• 5127686
• 5127688
• 5127689
• 5127690
• 5127691
• 5127692
• 5127693
• 5127694

Acknowledgments

<a href="https://x.com/soaj1664ashar">Dr.-Ing Ashar Javed</a>, <a href="https://x.com/ky0tofu">Ky0toFu</a>, <a href="https://novice-22.com/">novice-22</a>

Revision History

• 2026-10-13: Information published.