CVE-2026-58280: Uncontrolled recursion in .NET allows an unauthorized attacker to deny service over a network.

CVE-2026-58280 · Severity: high · CVSS 7.5 · Published 2026-10-13

.NET is a framework for building applications across Windows, Linux, and macOS. The System.Security.Cryptography.Xml and System.Private.Xml components fail to properly limit recursion depth when processing signed XML documents, allowing an attacker to craft a malicious XML file that causes the application to crash or become unresponsive. An organization using vulnerable .NET versions could lose service availability if their applications process untrusted XML input.

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-arm (NuGet), Microsoft.NetCore.App.Runtime.win-arm64 (NuGet), Microsoft.NetCore.App.Runtime.win-x64 (NuGet), Microsoft.NetCore.App.Runtime.win-x86 (NuGet). Vendors: Microsoft, NuGet.

Quick answers

Is CVE-2026-58280 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-58280 being exploited in the wild.
How severe is CVE-2026-58280?
High severity, with a CVSS score of 7.5, published 13 October 2026.
Which products and versions are affected?
Microsoft .Net 8.0.0 through 8.0.31, 9.0.0 through 9.0.20, 10.0.0 through 10.0.12, 11.0.0-preview.1 through 11.0.0-rc.1; Microsoft.NetCore.App.Runtime.linux-arm (NuGet) >= 9.0.0, <= 9.0.20; Microsoft.NetCore.App.Runtime.linux-arm64 (NuGet) >= 9.0.0, <= 9.0.20; Microsoft.NetCore.App.Runtime.linux-musl-arm (NuGet) >= 9.0.0, <= 9.0.20; and 9 more.
Is there a fix for CVE-2026-58280?
Yes: fixed in .NET 8.0.32, 9.0.21, 10.0.13, 11.0.0-rc.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-58280 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-58280?
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

  • Fixed in: .NET 8.0.32, 9.0.21, 10.0.13, 11.0.0-rc.2

Technical details

The vulnerability is an uncontrolled recursion issue (CWE-674) in .NET's XML cryptography and XML parsing components that lacks proper input-depth limits. An attacker with network access can send a specially crafted signed XML document to trigger excessive recursion, causing denial of service without requiring authentication or user interaction. The fix adds input-depth limits, operation-count limits, disables DTD processing by default, validates entity references, and bounds encrypted-data processing.

Affected products

  • Microsoft .NET 8.0.0 through 8.0.31, 9.0.0 through 9.0.20, 10.0.0 through 10.0.12, 11.0.0-preview.1 through 11.0.0-rc.1

Identifiers

  • CVE-2026-58280
  • GHSA-mc4q-93x5-f6hj

Timeline

  • 2026-10-13: disclosed

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