GHSA-x459-p2rx-f8ff
HIGHGHSA-x459-p2rx-f8ff is a high-severity (CVSS 7.5) vulnerability in Microsoft.AspNetCore.App.Runtime.win-x64. O3 Security confirms whether GHSA-x459-p2rx-f8ff is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
.NET Denial of Service Vulnerability
Blast Radius
Microsoft.AspNetCore.App.Runtime.win-x64.NETMicrosoft.AspNetCore.App.Runtime.linux-x64.NETMicrosoft.AspNetCore.App.Runtime.win-x86.NETMicrosoft.AspNetCore.App.Runtime.osx-x64.NETMicrosoft.AspNetCore.App.Runtime.linux-musl-x64.NETMicrosoft.AspNetCore.App.Runtime.linux-arm64.NETMicrosoft.AspNetCore.App.Runtime.linux-arm.NETMicrosoft.AspNetCore.App.Runtime.win-arm64+15 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
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.
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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.
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If you're using .NET 5.0, you should download and install Runtime 5.0.14 or SDK 5.0.114 (for Visual Studio 2019 v16.8) or SDK 5.0.405 (for Visual Studio 2011 v16.11) from https://dotnet.microsoft.com/download/dotnet-core/5.0.
.NET 6.0 and .NET 5.0 updates are also available from Microsoft Update. To access this either type "Check for updates" in your Windows search, or open Settings, choose Update & Security and then click Check for Updates.
Other Details
- Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/207
- An Issue for this can be found at https://github.com/dotnet/aspnetcore/issues/40072
- MSRC details for this can be found at https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2022-21986
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.win-x64 | ≥ 5.0.0&&< 5.0.14 | 5.0.14 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.linux-x64 | ≥ 5.0.0&&< 5.0.14 | 5.0.14 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.win-x86 | ≥ 5.0.0&&< 5.0.14 | 5.0.14 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.osx-x64 | ≥ 5.0.0&&< 5.0.14 | 5.0.14 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | ≥ 5.0.0&&< 5.0.14 | 5.0.14 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.linux-arm64 | ≥ 5.0.0&&< 5.0.14 | 5.0.14 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.AspNetCore.App.Runtime.win-x64. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Microsoft.AspNetCore.App.Runtime.win-x64 to 5.0.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x459-p2rx-f8ff is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-x459-p2rx-f8ff is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-x459-p2rx-f8ff. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-x459-p2rx-f8ff in your dependencies?
O3 detects GHSA-x459-p2rx-f8ff across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.