Vulnerability record · CVE-2026-33430 · published 26 March 2026
CVE-2026-33430: Beeware briefcase incorrect permission assignment vulnerability
Beeware · Briefcase
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.
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.
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://github.com/beeware/briefcase-windows-VisualStudio-template/pull/85 | Issue TrackingPatch |
| https://github.com/beeware/briefcase-windows-app-template/pull/86 | Issue TrackingPatch |
| https://github.com/beeware/briefcase/issues/2759 | Issue Tracking |
| https://github.com/beeware/briefcase/security/advisories/GHSA-r3r2-35v9-v238 | MitigationPatchVendor Advisory |
Track CVE-2026-33430 inside VULONE
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Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-33430), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.
