CVE-2026-26171 .NET Denial of Service Vulnerability
An unauthorized attacker can cause a denial of service in .NET and PowerShell via uncontrolled resource consumption.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-26171?
CVE-2026-26171 is a high-severity denial of service vulnerability in Microsoft .Net, published on 14 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Uncontrolled resource consumption in .NET allows an unauthorized attacker to deny service over a network.
Which versions are affected by CVE-2026-26171?
9 open source packages ship an affected version, including System.Security.Cryptography.Xml, dotnet and dotnet-sdk. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
System.Security.Cryptography.Xml NuGet | From 10.0.0 | 10.0.6 |
System.Security.Cryptography.Xml NuGet | From 10.0.0 | 10.0.6 |
System.Security.Cryptography.Xml NuGet | From 8.0.0 | 8.0.3 |
System.Security.Cryptography.Xml NuGet | From 8.0.0 | 8.0.3 |
System.Security.Cryptography.Xml NuGet | From 9.0.0 | 9.0.15 |
System.Security.Cryptography.Xml NuGet | From 9.0.0 | 9.0.15 |
3 more packages
dotnet Bitnami | From 8.0.0 | 8.0.26, 9.0.15, 10.0.6 |
dotnet-sdk Bitnami | From 8.0.0 | 8.0.26, 9.0.15, 10.0.6 |
powershell Bitnami | From 7.5.0 | 7.5.6, 7.6.1 |
Products include Microsoft .Net, Microsoft Powershell.
How do I fix CVE-2026-26171?
Upgrade System.Security.Cryptography.Xml to a fixed version for your release line: 10.0.6, 8.0.3 or 9.0.15.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-26171 being exploited?
There is no known exploitation of CVE-2026-26171 in the wild and no public exploit code.
Other vulnerabilities in Microsoft .Net
- CVE-2024-43498 .NET and Visual Studio Remote Code Execution Vulnerability
- CVE-2024-0057 NET, .NET Framework, and Visual Studio Security Feature Bypass Vulnerability
- CVE-2026-96957 .NET Security Feature Bypass Vulnerability
- CVE-2026-69439 .NET and Visual Studio Elevation of Privilege Vulnerability
- CVE-2026-71328 .NET and Visual Studio Remote Code Execution Vulnerability
Sources
Also known as BELL-CVE-2026-26171, BIT-dotnet-2026-26171, BIT-dotnet-sdk-2026-26171, BIT-powershell-2026-26171, ECHO-08ee-db76-1049, GHSA-w3x6-4m5h-cxqf and 11 more.