Microsoft Security Advisory CVE-2026-118740 - Aspire Security Feature Bypass Vulnerability

Exploitation

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

CVSS

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

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 Aspire. This advisory provides guidance on updating affected applications and components. Aspire Dashboard's unauthenticated NotFound route can permit telemetry deletion in both standalone and AppHost-hosted deployments. In standalone deployments using browser-token authentication, it can also expose the browser token. Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/526 CVSS Details - Version: 3.1 - Severity: Critical - Score: 9.1 - Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness: CWE-862 Affected Platforms - Platforms: Any supported OS - Architectures: x64, Arm64 <a name="affected-packages"</aAffected Packages Standalone Aspire Dashboard Package | Affected version | Patched version --- | --- | --- Aspire Dashboard | < 13.6.5 | 13.6.5 Both 13.6.3 and 13.6.4 contain the unauthenticated NotFound route.…

Published by the source

12 Nov 2026, 17:17 UTC

Last modified by the source

12 Nov 2026, 17:17 UTC

Source last checked

12 Nov 2026, 18:20 UTC

1. Revision 1 · created · 12 Nov 2026

   Published from ghsa record GHSA-4g86-54fm-h9h8

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# Patch Next advisory brief: CVE-2026-118740

Advisory: Microsoft Security Advisory CVE-2026-118740 - Aspire Security Feature Bypass Vulnerability
IDs: CVE-2026-118740, GHSA-4g86-54fm-h9h8
Record: https://patchnext.com/advisories/cve-2026-118740 (revision 1, source checked 12 Nov 2026, 18:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: aspire.dashboard.sdk.osx-arm64 13.6.5; aspire.dashboard.sdk.linux-x64 13.6.5; aspire.dashboard.sdk.win-arm64 13.6.5; aspire.dashboard.sdk.linux-arm64 13.6.5; aspire.dashboard.sdk.osx-x64 13.6.5; aspire.dashboard.sdk.linux-musl-x64 13.6.5; aspire.dashboard.sdk.win-x64 13.6.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet aspire.dashboard.sdk.osx-arm64: affected < 13.6.5; fixed in 13.6.5
- NuGet aspire.dashboard.sdk.linux-x64: affected < 13.6.5; fixed in 13.6.5
- NuGet aspire.dashboard.sdk.win-arm64: affected < 13.6.5; fixed in 13.6.5
- NuGet aspire.dashboard.sdk.linux-arm64: affected < 13.6.5; fixed in 13.6.5
- NuGet aspire.dashboard.sdk.osx-x64: affected < 13.6.5; fixed in 13.6.5
- NuGet aspire.dashboard.sdk.linux-musl-x64: affected < 13.6.5; fixed in 13.6.5
- NuGet aspire.dashboard.sdk.win-x64: affected < 13.6.5; fixed in 13.6.5

## Suggested inspection (read-only)
- NuGet aspire.dashboard.sdk.osx-arm64: check the installed version with your package manager.
- NuGet aspire.dashboard.sdk.linux-x64: check the installed version with your package manager.
- NuGet aspire.dashboard.sdk.win-arm64: check the installed version with your package manager.
- NuGet aspire.dashboard.sdk.linux-arm64: check the installed version with your package manager.
- NuGet aspire.dashboard.sdk.osx-x64: check the installed version with your package manager.
- NuGet aspire.dashboard.sdk.linux-musl-x64: check the installed version with your package manager.
- NuGet aspire.dashboard.sdk.win-x64: 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 aspire.dashboard.sdk.osx-arm64, aspire.dashboard.sdk.linux-x64, aspire.dashboard.sdk.win-arm64, aspire.dashboard.sdk.linux-arm64, aspire.dashboard.sdk.osx-x64, aspire.dashboard.sdk.linux-musl-x64, aspire.dashboard.sdk.win-x64.
- 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-4g86-54fm-h9h8 (GitHub-reviewed advisory GHSA-4g86-54fm-h9h8 lists affected ranges: NuGet aspire.dashboard.sdk.linux-x64 >=0 =0 =0 =0 =0 =0 =0 <13.6.5)

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