Denial of service vulnerability exists when System.IO.Pipelines improperly handles requests

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-2018-8409: 6.56% estimated exploitation activity in the next 30 days; percentile 93.82 (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.

A denial of service vulnerability exists when System.IO.Pipelines improperly handles requests, aka "System.IO.Pipelines Denial of Service." This affects .NET Core 2.1, System.IO.Pipelines, ASP.NET Core 2.1.

Published by the source

16 Oct 2018, 19:56 UTC

Last modified by the source

29 Jan 2023, 05:06 UTC

Source last checked

26 Oct 2026, 16:58 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-j378-6mmw-hqfr

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# Patch Next advisory brief: CVE-2018-8409

Advisory: Denial of service vulnerability exists when System.IO.Pipelines improperly handles requests
IDs: CVE-2018-8409, GHSA-j378-6mmw-hqfr
Record: https://patchnext.com/advisories/cve-2018-8409 (revision 1, source checked 26 Oct 2026, 16:58 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: system.io.pipelines 4.5.1; microsoft.aspnetcore.all 2.1.4; microsoft.aspnetcore.app 2.1.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet system.io.pipelines: affected >= 4.5.0, <= 4.5.0; fixed in 4.5.1
- NuGet microsoft.aspnetcore.all: affected >= 2.1.0, <= 2.1.3; fixed in 2.1.4
- NuGet microsoft.aspnetcore.app: affected >= 2.1.0, <= 2.1.3; fixed in 2.1.4

## Suggested inspection (read-only)
- NuGet system.io.pipelines: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.all: check the installed version with your package manager.
- NuGet microsoft.aspnetcore.app: 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 system.io.pipelines, microsoft.aspnetcore.all, microsoft.aspnetcore.app.
- 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-j378-6mmw-hqfr (GitHub-reviewed advisory GHSA-j378-6mmw-hqfr lists affected ranges: NuGet microsoft.aspnetcore.all >=2.1.0 =2.1.0 =4.5.0 <=4.5.0)

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