.NET Denial of Service Vulnerability

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2022-21986: 3.74% estimated exploitation activity in the next 30 days; percentile 89.86 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 6.0 and .NET 5.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A Denial of Service vulnerability exists in .NET 6.0 and .NET 5.0 when the Kestrel web server processes certain HTTP/2 and HTTP/3 requests. Affected Software Any .NET 6.0 application running on .NET 6.0.1 or lower. Any .NET 5.0 application running on .NET 5.0.13 or lower. Patches To fix the issue, please install the latest version of .NET 6.0 or .NET 5.0. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET SDKs. If you're using .NET Core 6.0, you should download and install Runtime 6.0.2 or SDK 6.0.102 (for Visual Studio 2022 v17.1) from https://dotnet.microsoft.com/download/dotnet-core/6.0. If you're using .NET 5.0, you should download and install…

Published by the source

21 Oct 2022, 20:29 UTC

Last modified by the source

30 Jun 2023, 20:01 UTC

Source last checked

26 Oct 2026, 16:59 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-x459-p2rx-f8ff

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# Patch Next advisory brief: CVE-2022-21986

Advisory: .NET Denial of Service Vulnerability
IDs: CVE-2022-21986, GHSA-x459-p2rx-f8ff
Record: https://patchnext.com/advisories/cve-2022-21986 (revision 1, source checked 26 Oct 2026, 16:59 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: microsoft.aspnetcore.app.runtime.linux-arm64 6.0.2, 5.0.14; microsoft.aspnetcore.app.runtime.linux-musl-arm64 6.0.2, 5.0.14; microsoft.aspnetcore.app.runtime.osx-x64 6.0.2, 5.0.14; microsoft.aspnetcore.app.runtime.linux-arm 6.0.2, 5.0.14; microsoft.aspnetcore.app.runtime.win-x86 6.0.2, 5.0.14; microsoft.aspnetcore.app.runtime.linux-x64 6.0.2, 5.0.14; microsoft.aspnetcore.app.runtime.linux-musl-arm 6.0.2, 5.0.14; microsoft.aspnetcore.app.runtime.win-arm 6.0.2, 5.0.14; microsoft.aspnetcore.app.runtime.linux-musl-x64 6.0.2, 5.0.14; microsoft.aspnetcore.app.runtime.osx-arm64 6.0.2; microsoft.aspnetcore.app.runtime.win-x64 6.0.2, 5.0.14; microsoft.aspnetcore.app.runtime.win-arm64 6.0.2, 5.0.14. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet microsoft.aspnetcore.app.runtime.linux-arm64: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.linux-musl-arm64: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.osx-x64: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.linux-arm: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.win-x86: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.linux-x64: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.linux-musl-arm: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.win-arm: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.linux-musl-x64: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.osx-arm64: affected >= 6.0.0, < 6.0.2; fixed in 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.win-x64: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2
- NuGet microsoft.aspnetcore.app.runtime.win-arm64: affected >= 5.0.0, < 5.0.14; >= 6.0.0, < 6.0.2; fixed in 5.0.14, 6.0.2

## Suggested inspection (read-only)
- NuGet microsoft.aspnetcore.app.runtime.linux-arm64: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.linux-musl-arm64: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.osx-x64: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.linux-arm: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.win-x86: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.linux-x64: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.linux-musl-arm: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.win-arm: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.linux-musl-x64: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.osx-arm64: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.win-x64: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app.runtime.win-arm64: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on microsoft.aspnetcore.app.runtime.linux-arm64, microsoft.aspnetcore.app.runtime.linux-musl-arm64, microsoft.aspnetcore.app.runtime.osx-x64, microsoft.aspnetcore.app.runtime.linux-arm, microsoft.aspnetcore.app.runtime.win-x86, microsoft.aspnetcore.app.runtime.linux-x64, microsoft.aspnetcore.app.runtime.linux-musl-arm, microsoft.aspnetcore.app.runtime.win-arm, microsoft.aspnetcore.app.runtime.linux-musl-x64, microsoft.aspnetcore.app.runtime.osx-arm64, microsoft.aspnetcore.app.runtime.win-x64, microsoft.aspnetcore.app.runtime.win-arm64.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-x459-p2rx-f8ff (GitHub-reviewed advisory GHSA-x459-p2rx-f8ff lists affected ranges: NuGet microsoft.aspnetcore.app.runtime.win-x64 >=5.0.0 =6.0.0 =5.0.0 =6.0.0 =5.0.0 =6.0.0 =5.0.0 =6.0.0 =5.0.0 =6.0.0 <6.0.2; NuGet…)

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