Briefcase is a tool for converting a Python project into a standalone native application. Starting in version 0.3.0 and prior to version 0.3.26, if a developer uses Briefcase to produce an Windows MSI installer for a project, and that project is installed for All Users (i.e., per-machine scope), the installation process creates an directory that inherits all the permissions of the parent directory. Depending on the location chosen by the installing user, this may allow a low privilege but authenticated user to replace or modify the binaries installed by the application. If an administrator then runs the altered binary, the binary will run with elevated privileges. The problem is caused by the template used to generate the WXS file for Windows projects. It was fixed in the templates used in Briefcase 0.3.26, 0.4.0, and 0.4.1. Re-running `briefcase create` on your Briefcase project will result in the updated templates being used. As a workaround, the patch can be added to any existing Briefcase .wxs file generated by Briefcase 0.3.24 or later.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-r3r2-35v9-v238 Briefcase: Windows MSI Installer Privilege Escalation via Insecure Directory Permissions
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 26 Mar 2026 17:15:00 +0000

Type Values Removed Values Added
Description Briefcase is a tool for converting a Python project into a standalone native application. Starting in version 0.3.0 and prior to version 0.3.26, if a developer uses Briefcase to produce an Windows MSI installer for a project, and that project is installed for All Users (i.e., per-machine scope), the installation process creates an directory that inherits all the permissions of the parent directory. Depending on the location chosen by the installing user, this may allow a low privilege but authenticated user to replace or modify the binaries installed by the application. If an administrator then runs the altered binary, the binary will run with elevated privileges. The problem is caused by the template used to generate the WXS file for Windows projects. It was fixed in the templates used in Briefcase 0.3.26, 0.4.0, and 0.4.1. Re-running `briefcase create` on your Briefcase project will result in the updated templates being used. As a workaround, the patch can be added to any existing Briefcase .wxs file generated by Briefcase 0.3.24 or later.
Title Briefcase: Windows MSI Installer Privilege Escalation via Insecure Directory Permissions
Weaknesses CWE-732
References
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-26T18:24:04.179Z

Reserved: 2026-03-19T18:45:22.435Z

Link: CVE-2026-33430

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-26T17:16:38.713

Modified: 2026-03-26T17:16:38.713

Link: CVE-2026-33430

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses