Microsoft Security Advisory CVE-2026-114157 - ASP.NET Core Security Feature Bypass Vulnerability

Exploitation

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

CVSS

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

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core's Kestrel Named Pipes transport. This advisory provides guidance on updating affected applications and components. A Kestrel named-pipe listener configured with `CurrentUserOnly` can lose protected namespace ownership during recovery, allowing another local user to claim the pipe path.

Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/507

CVSS Details - Version: 3.1 - Severity: High - Score: 7.5 (base score) - Vector: `CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N/E:U/RL:O/RC:C` - Weakness: CWE-362 - MSRC severity: Important - Impact: Security Feature Bypass

Affected Platforms - Platforms: Windows - Architectures: Arm64, x64, x86

Affected Packages Microsoft.AspNetCore.Server.Kestrel.Transport.NamedPipes ships in the ASP.NET Core shared framework and runtime…

Published by the source

11 Nov 2026, 00:25 UTC

Last modified by the source

11 Nov 2026, 00:30 UTC

Source last checked

11 Nov 2026, 07:45 UTC

1. Revision 2 · amended · 11 Nov 2026

   Amended from osv record GHSA-7phj-vgxq-r67h

2. Revision 1 · created · 11 Nov 2026

   Published from ghsa record GHSA-7phj-vgxq-r67h

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# Patch Next advisory brief: CVE-2026-114157

Advisory: Microsoft Security Advisory CVE-2026-114157 - ASP.NET Core Security Feature Bypass Vulnerability
IDs: CVE-2026-114157, GHSA-7phj-vgxq-r67h
Record: https://patchnext.com/advisories/cve-2026-114157 (revision 2, source checked 11 Nov 2026, 07:45 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.win-x86 11.0.0, 10.0.15, 9.0.23, 8.0.34; microsoft.aspnetcore.app.runtime.win-x64 11.0.0, 10.0.15, 9.0.23, 8.0.34; microsoft.aspnetcore.app.runtime.win-arm64 11.0.0, 10.0.15, 9.0.23, 8.0.34. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet microsoft.aspnetcore.app.runtime.win-x86: affected >= 8.0.0-preview.1.23112.2, < 8.0.34; >= 9.0.0-preview.1.24081.5, < 9.0.23; >= 10.0.0-preview.1.25120.3, < 10.0.15; >= 11.0.0-preview.1.26104.118, < 11.0.0; fixed in 9.0.23, 8.0.34, 10.0.15, 11.0.0
- NuGet microsoft.aspnetcore.app.runtime.win-x64: affected >= 8.0.0-preview.1.23112.2, < 8.0.34; >= 9.0.0-preview.1.24081.5, < 9.0.23; >= 10.0.0-preview.1.25120.3, < 10.0.15; >= 11.0.0-preview.1.26104.118, < 11.0.0; fixed in 9.0.23, 8.0.34, 10.0.15, 11.0.0
- NuGet microsoft.aspnetcore.app.runtime.win-arm64: affected >= 8.0.0-preview.1.23112.2, < 8.0.34; >= 9.0.0-preview.1.24081.5, < 9.0.23; >= 10.0.0-preview.1.25120.3, < 10.0.15; >= 11.0.0-preview.1.26104.118, < 11.0.0; fixed in 9.0.23, 8.0.34, 10.0.15, 11.0.0

## 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.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.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-7phj-vgxq-r67h (GitHub-reviewed advisory GHSA-7phj-vgxq-r67h lists affected ranges: NuGet microsoft.aspnetcore.app.runtime.win-arm64 >=8.0.0-preview.1.23112.2 =9.0.0-preview.1.24081.5 =10.0.0-preview.1.25120.3 =11.0.0-preview.1.26104.118 =8.0.0-preview.1.23112.2 =9.0.0-preview.1.24081.5 =10.0.0-preview.1.25120.3 =11.0.0-preview.1.26104.118 <=11.0.0-rc.3.26522.148; NuGet…)
- Verified: https://osv.dev/vulnerability/GHSA-7phj-vgxq-r67h (OSV record GHSA-7phj-vgxq-r67h lists affected ranges: NuGet microsoft.aspnetcore.app.runtime.win-arm64 >=8.0.0-preview.1.23112.2 =9.0.0-preview.1.24081.5 =10.0.0-preview.1.25120.3 =11.0.0-preview.1.26104.118 =8.0.0-preview.1.23112.2 =9.0.0-preview.1.24081.5 =10.0.0-preview.1.25120.3 =11.0.0-preview.1.26104.118 <11.0.0…)

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