Microsoft Security Advisory CVE-2026-120778 - Aspire Elevation of Privilege Vulnerability

Exploitation

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

CVSS

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

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 the Aspire CLI. This advisory provides guidance on updating affected applications and components. An insecure temporary directory used by Aspire CLI-generated builds can allow a local attacker to influence MSBuild response-file discovery and execute code with the privileges of the developer running the CLI.

Announcement Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/519

CVSS Details - Version: 3.1 - Severity: High - Score: 7.3 - Vector: `CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H` - Weakness: CWE-379 (Creation of Temporary File in Directory with Insecure Permissions) - MSRC severity: Important

Affected Platforms - Platforms: Linux, macOS - Architectures: x64, Arm64

Affected Packages

Standalone Aspire CLI Package | Affected version | Patched version --- | --- | ---…

Published by the source

11 Nov 2026, 00:30 UTC

Last modified by the source

11 Nov 2026, 00:45 UTC

Source last checked

11 Nov 2026, 06:00 UTC

1. Revision 2 · amended · 11 Nov 2026

   Amended from osv record GHSA-m63f-xhvm-6mv5

2. Revision 1 · created · 11 Nov 2026

   Published from ghsa record GHSA-m63f-xhvm-6mv5

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# Patch Next advisory brief: CVE-2026-120778

Advisory: Microsoft Security Advisory CVE-2026-120778 - Aspire Elevation of Privilege Vulnerability
IDs: CVE-2026-120778, GHSA-m63f-xhvm-6mv5
Record: https://patchnext.com/advisories/cve-2026-120778 (revision 2, source checked 11 Nov 2026, 06:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: aspire.cli.linux-musl-x64 13.6.5; aspire.cli.linux-arm64 13.6.5; @microsoft/aspire-cli-osx-x64 13.6.5; aspire.cli.osx-x64 13.6.5; @microsoft/aspire-cli-linux-musl-x64 13.6.5; aspire.cli 13.6.5; @microsoft/aspire-cli-linux-x64 13.6.5; @microsoft/aspire-cli-linux-arm64 13.6.5; @microsoft/aspire-cli 13.6.5; aspire.cli.linux-x64 13.6.5; aspire.cli.osx-arm64 13.6.5; @microsoft/aspire-cli-osx-arm64 13.6.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet aspire.cli.linux-musl-x64: affected >= 13.3.0, < 13.6.5; fixed in 13.6.5
- NuGet aspire.cli.linux-arm64: affected >= 13.3.0, < 13.6.5; fixed in 13.6.5
- npm @microsoft/aspire-cli-osx-x64: affected >= 13.4.2, < 13.6.5; fixed in 13.6.5
- NuGet aspire.cli.osx-x64: affected >= 13.3.0, < 13.6.5; fixed in 13.6.5
- npm @microsoft/aspire-cli-linux-musl-x64: affected >= 13.4.2, < 13.6.5; fixed in 13.6.5
- NuGet aspire.cli: affected >= 13.2.0, < 13.6.5; fixed in 13.6.5
- npm @microsoft/aspire-cli-linux-x64: affected >= 13.4.2, < 13.6.5; fixed in 13.6.5
- npm @microsoft/aspire-cli-linux-arm64: affected >= 13.4.2, < 13.6.5; fixed in 13.6.5
- npm @microsoft/aspire-cli: affected >= 13.4.2, < 13.6.5; fixed in 13.6.5
- NuGet aspire.cli.linux-x64: affected >= 13.3.0, < 13.6.5; fixed in 13.6.5
- NuGet aspire.cli.osx-arm64: affected >= 13.3.0, < 13.6.5; fixed in 13.6.5
- npm @microsoft/aspire-cli-osx-arm64: affected >= 13.4.2, < 13.6.5; fixed in 13.6.5

## Suggested inspection (read-only)
- NuGet aspire.cli.linux-musl-x64: check the installed version with your package manager.
- NuGet aspire.cli.linux-arm64: check the installed version with your package manager.
- `npm ls @microsoft/aspire-cli-osx-x64 --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- NuGet aspire.cli.osx-x64: check the installed version with your package manager.
- `npm ls @microsoft/aspire-cli-linux-musl-x64 --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- NuGet aspire.cli: check the installed version with your package manager.
- `npm ls @microsoft/aspire-cli-linux-x64 --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @microsoft/aspire-cli-linux-arm64 --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @microsoft/aspire-cli --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- NuGet aspire.cli.linux-x64: check the installed version with your package manager.
- NuGet aspire.cli.osx-arm64: check the installed version with your package manager.
- `npm ls @microsoft/aspire-cli-osx-arm64 --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## 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.cli.linux-musl-x64, aspire.cli.linux-arm64, @microsoft/aspire-cli-osx-x64, aspire.cli.osx-x64, @microsoft/aspire-cli-linux-musl-x64, aspire.cli, @microsoft/aspire-cli-linux-x64, @microsoft/aspire-cli-linux-arm64, @microsoft/aspire-cli, aspire.cli.linux-x64, aspire.cli.osx-arm64, @microsoft/aspire-cli-osx-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-m63f-xhvm-6mv5 (GitHub-reviewed advisory GHSA-m63f-xhvm-6mv5 lists affected ranges: NuGet aspire.cli >=13.2.0 =13.3.0 =13.3.0 =13.3.0 =13.3.0 =13.3.0 =13.4.2 =13.4.2 =13.4.2 <13.6.5; npm…)
- Verified: https://osv.dev/vulnerability/GHSA-m63f-xhvm-6mv5 (OSV record GHSA-m63f-xhvm-6mv5 lists affected ranges: NuGet aspire.cli >=13.2.0 =13.3.0 =13.3.0 =13.3.0 =13.3.0 =13.3.0 =13.4.2 =13.4.2 <13.6.5 (fixed); npm…)

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