CVE-2026-96959 .NET Denial of Service Vulnerability

High 7.5 Published Updated

An unauthorized attacker can cause a denial of service in .NET Framework by exploiting uncontrolled resource allocation.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-96959?

CVE-2026-96959 is a high-severity denial of service vulnerability in Microsoft .Net, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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

Weakness: CWE-770

Which versions are affected by CVE-2026-96959?

10 open source packages ship an affected version, including System.Security.Cryptography.Xml, dotnet and dotnet-sdk. It affects 2 products.

PackageAffectedFixed in
System.Security.Cryptography.Xml NuGetFrom 10.0.010.0.13
System.Security.Cryptography.Xml NuGetFrom 10.0.010.0.13
System.Security.Cryptography.Xml NuGetFrom 11.0.0-preview.111.0.0-rc.2
System.Security.Cryptography.Xml NuGetFrom 11.0.0-preview.111.0.0-rc.2
System.Security.Cryptography.Xml NuGetFrom 8.0.08.0.5
System.Security.Cryptography.Xml NuGetFrom 8.0.08.0.5
4 more packages
System.Security.Cryptography.Xml NuGetFrom 9.0.09.0.21
System.Security.Cryptography.Xml NuGetFrom 9.0.09.0.21
dotnet BitnamiFrom 8.0.08.0.5, 9.0.21, 10.0.13
dotnet-sdk BitnamiFrom 8.0.08.0.5, 9.0.21, 10.0.13

Products include Microsoft .Net, Microsoft .Net Framework.

How do I fix CVE-2026-96959?

Upgrade System.Security.Cryptography.Xml to a fixed version for your release line: 10.0.13, 11.0.0-rc.2, 8.0.5 or 9.0.21.

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-2026-96959 being exploited?

There is no known exploitation of CVE-2026-96959 in the wild and no public exploit code.

All Microsoft .Net vulnerabilities

Sources

Also known as BIT-dotnet-2026-96959, BIT-dotnet-sdk-2026-96959, ECHO-a9c4-3288-b534, GHSA-c399-9853-6jmj, MINI-3jvm-rppm-h6h2, MINI-7434-xc6v-2f44 and 6 more.

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