High, CVSS 7.3PyPIAmendedPublished
Briefcase: Windows MSI Installer Privilege Escalation via Insecure Directory Permissions
CVE-2026-33430 · GHSA-r3r2-35v9-v238
- Affected
- PyPI briefcase >= 0.3.0, < 0.3.26
- Fixed in
- 0.3.26· Vendor fix available
- Issue
- Impact 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. Patches The problem is caused by the template used to generate the WXS file for Windows projects. It was fixed with the following PRs: beeware/briefcase-windows-app-template#86 beeware/briefcase-windows-VisualStudio-template#85 These patches have been backported to 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. Workarounds The change from…
Recommended action: Upgrade to 0.3.26 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.