CVE-2026-33430
Briefcase: Windows MSI Installer Privilege Escalation via Insecure Directory Permissions
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.
INFO
Published Date :
March 26, 2026, 5:16 p.m.
Last Modified :
March 26, 2026, 5:16 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-33430
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Briefcase to version 0.3.26 or later.
- Re-run 'briefcase create' on your project.
- Apply patch to existing .wxs files if not updating.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-33430.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-33430 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-33430
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-33430 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-33430 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Mar. 26, 2026
Action Type Old Value New Value 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. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-732 Added Reference https://github.com/beeware/briefcase/issues/2759 Added Reference https://github.com/beeware/briefcase/security/advisories/GHSA-r3r2-35v9-v238 Added Reference https://github.com/beeware/briefcase-windows-app-template/pull/86 Added Reference https://github.com/beeware/briefcase-windows-VisualStudio-template/pull/85