.NET Denial of Service Vulnerability

Exploitation

Confirmed: listed in the CISA Known Exploited Vulnerabilities catalog.

CVSS

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

EPSS

• CVE-2023-38180: 14.13% estimated exploitation activity in the next 30 days; percentile 96.58 (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 Security Advisory CVE-2023-38180: .NET Denial of Service Vulnerability <a name="executive-summary"</aExecutive summary Microsoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core 2.1, .NET 6.0, and .NET 7.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A vulnerability exists in Kestrel where, on detecting a potentially malicious client, Kestrel will sometimes fail to disconnect it, resulting in denial of service. Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/269 <a name="mitigation-factors"</aMitigation factors If your application is running behind a reverse proxy, or Web Application Firewall, which has its own mitigations against HTTP based attacks this issue may be mitigated by the proxy or WAF <a name="affected-software"</aAffected software Any .NET 7.0 application running on .NET 7.0.8 or…

Published by the source

9 Aug 2023, 12:56 UTC

Last modified by the source

22 Oct 2025, 19:21 UTC

Source last checked

26 Oct 2026, 17:04 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vmch-3w2x-vhgq

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# Patch Next advisory brief: CVE-2023-38180

Advisory: .NET Denial of Service Vulnerability
IDs: CVE-2023-38180, GHSA-vmch-3w2x-vhgq
Record: https://patchnext.com/advisories/cve-2023-38180 (revision 1, source checked 26 Oct 2026, 17:04 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: confirmed: listed in the CISA Known Exploited Vulnerabilities catalog.
Vendor response: Vendor fix available; fixed versions by package: microsoft.aspnetcore.app.runtime.win-x86 7.0.10, 6.0.21; microsoft.aspnetcore.app.runtime.win-x64 7.0.10, 6.0.21; microsoft.aspnetcore.server.kestrel.transport.libuv 6.0.21, 2.1.40; microsoft.aspnetcore.server.kestrel.transport.sockets 2.1.40; microsoft.aspnetcore.app.runtime.win-arm64 7.0.10, 6.0.21. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet microsoft.aspnetcore.app.runtime.win-x86: affected >= 7.0.0, <= 7.0.9; >= 6.0.0, <= 6.0.20; fixed in 6.0.21, 7.0.10
- NuGet microsoft.aspnetcore.app.runtime.win-x64: affected >= 7.0.0, <= 7.0.9; >= 6.0.0, <= 6.0.20; fixed in 6.0.21, 7.0.10
- NuGet microsoft.aspnetcore.server.kestrel.transport.libuv: affected >= 6.0.0, <= 6.0.20; <= 2.1.39; fixed in 6.0.21, 2.1.40
- NuGet microsoft.aspnetcore.server.kestrel.transport.sockets: affected <= 2.1.39; fixed in 2.1.40
- NuGet microsoft.aspnetcore.app.runtime.win-arm64: affected >= 7.0.0, <= 7.0.9; >= 6.0.0, <= 6.0.20; fixed in 6.0.21, 7.0.10

## Suggested inspection (read-only)
- NuGet microsoft.aspnetcore.app.runtime.win-x86: 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.server.kestrel.transport.libuv: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.server.kestrel.transport.sockets: 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.win-x86, microsoft.aspnetcore.app.runtime.win-x64, microsoft.aspnetcore.server.kestrel.transport.libuv, microsoft.aspnetcore.server.kestrel.transport.sockets, 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?
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-vmch-3w2x-vhgq (GitHub-reviewed advisory GHSA-vmch-3w2x-vhgq lists affected ranges: NuGet microsoft.aspnetcore.app.runtime.win-arm64 >=7.0.0 =6.0.0 =7.0.0 =6.0.0 =7.0.0 =6.0.0 =6.0.0 =0 =0 <=2.1.39)
- Verified: https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CISA added CVE-2023-38180 to the Known Exploited Vulnerabilities catalog on 2023-08-09.)

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