CVE-2026-120796: Microsoft .NET algorithmic complexity denial of service

CVE-2026-120796 · Severity: medium · CVSS 5.3 · Published 2026-11-10

.NET is Microsoft's development platform used to build applications and web services. An attacker on the network can exploit inefficient processing logic to overwhelm the system and make applications unavailable, disrupting business operations.

Technologies: Microsoft .Net, Microsoft.NetCore.App.Runtime.linux-arm (NuGet), Microsoft.NetCore.App.Runtime.linux-arm64 (NuGet), Microsoft.NetCore.App.Runtime.linux-musl-arm (NuGet), Microsoft.NetCore.App.Runtime.linux-musl-arm64 (NuGet), Microsoft.NetCore.App.Runtime.linux-musl-x64 (NuGet), Microsoft.NetCore.App.Runtime.linux-x64 (NuGet), Microsoft.NetCore.App.Runtime.osx-arm64 (NuGet), Microsoft.NetCore.App.Runtime.osx-x64 (NuGet), Microsoft.NetCore.App.Runtime.win-arm64 (NuGet), Microsoft.NetCore.App.Runtime.win-x64 (NuGet), Microsoft.NetCore.App.Runtime.win-x86 (NuGet), System.Text.Json (NuGet). Vendors: Microsoft, NuGet.

Quick answers

Is CVE-2026-120796 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-120796 being exploited in the wild.
How severe is CVE-2026-120796?
Medium severity, with a CVSS score of 5.3, published 10 November 2026.
Which products and versions are affected?
Microsoft.NetCore.App.Runtime.linux-arm (NuGet) >= 11.0.0-preview.1.26104.118, <= 11.0.0-rc.3.26522.148, ECOSYSTEM:introduced=11.0.0-preview.1.26104.118,fixed=11.0.0; Microsoft.NetCore.App.Runtime.linux-arm64 (NuGet) >= 11.0.0-preview.1.26104.118, <= 11.0.0-rc.3.26522.148, ECOSYSTEM:introduced=11.0.0-preview.1.26104.118,fixed=11.0.0; Microsoft.NetCore.App.Runtime.linux-musl-arm (NuGet) >= 11.0.0-preview.1.26104.118, <= 11.0.0-rc.3.26522.148, ECOSYSTEM:introduced=11.0.0-preview.1.26104.118,fixed=11.0.0; Microsoft.NetCore.App.Runtime.linux-musl-arm64 (NuGet) >= 11.0.0-preview.1.26104.118, <= 11.0.0-rc.3.26522.148, ECOSYSTEM:introduced=11.0.0-preview.1.26104.118,fixed=11.0.0; and 8 more.
Is there a fix for CVE-2026-120796?
Yes. Microsoft.NetCore.App.Runtime.linux-arm (NuGet): upgrade to 11.0.0 or later; Microsoft.NetCore.App.Runtime.linux-arm64 (NuGet): upgrade to 11.0.0 or later; Microsoft.NetCore.App.Runtime.linux-musl-arm (NuGet): upgrade to 11.0.0 or later; Microsoft.NetCore.App.Runtime.linux-musl-arm64 (NuGet): upgrade to 11.0.0 or later; Microsoft.NetCore.App.Runtime.linux-musl-x64 (NuGet): upgrade to 11.0.0 or later; Microsoft.NetCore.App.Runtime.linux-x64 (NuGet): upgrade to 11.0.0 or later; Microsoft.NetCore.App.Runtime.osx-arm64 (NuGet): upgrade to 11.0.0 or later; Microsoft.NetCore.App.Runtime.osx-x64 (NuGet): upgrade to 11.0.0 or later; Microsoft.NetCore.App.Runtime.win-arm64 (NuGet): upgrade to 11.0.0 or later; Microsoft.NetCore.App.Runtime.win-x64 (NuGet): upgrade to 11.0.0 or later; Microsoft.NetCore.App.Runtime.win-x86 (NuGet): upgrade to 11.0.0 or later; System.Text.Json (NuGet): upgrade to 11.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-120796 attacked?
It is attacked over the network.
Am I affected by CVE-2026-120796?
Check whether you run Microsoft .Net, Microsoft.NetCore.App.Runtime.linux-arm (NuGet), Microsoft.NetCore.App.Runtime.linux-arm64 (NuGet) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • Microsoft.NetCore.App.Runtime.linux-arm (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.linux-arm --version 11.0.0
  • Microsoft.NetCore.App.Runtime.linux-arm64 (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.linux-arm64 --version 11.0.0
  • Microsoft.NetCore.App.Runtime.linux-musl-arm (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.linux-musl-arm --version 11.0.0
  • Microsoft.NetCore.App.Runtime.linux-musl-arm64 (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.linux-musl-arm64 --version 11.0.0
  • Microsoft.NetCore.App.Runtime.linux-musl-x64 (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.linux-musl-x64 --version 11.0.0
  • Microsoft.NetCore.App.Runtime.linux-x64 (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.linux-x64 --version 11.0.0
  • Microsoft.NetCore.App.Runtime.osx-arm64 (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.osx-arm64 --version 11.0.0
  • Microsoft.NetCore.App.Runtime.osx-x64 (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.osx-x64 --version 11.0.0
  • Microsoft.NetCore.App.Runtime.win-arm64 (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.win-arm64 --version 11.0.0
  • Microsoft.NetCore.App.Runtime.win-x64 (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.win-x64 --version 11.0.0
  • Microsoft.NetCore.App.Runtime.win-x86 (NuGet): upgrade to 11.0.0 or later
    dotnet add package Microsoft.NetCore.App.Runtime.win-x86 --version 11.0.0
  • System.Text.Json (NuGet): upgrade to 11.0.0 or later
    dotnet add package System.Text.Json --version 11.0.0

Technical details

Inefficient algorithmic complexity in .NET allows an attacker to craft specific inputs that trigger computationally expensive operations, leading to a denial of service condition. The vulnerability is remotely exploitable over the network without authentication required. An attacker can cause application unavailability or performance degradation.

Affected products

  • Microsoft .NET

Identifiers

  • CVE-2026-120796
  • GHSA-cpw3-h88j-9f6x

Timeline

  • 2026-11-10: disclosed

References

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