{"id":"GHSA-r3r2-35v9-v238","summary":"Briefcase: Windows MSI Installer Privilege Escalation via Insecure Directory Permissions ","details":"### Impact\n\nIf 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.\n\n### Patches\n\nThe problem is caused by the template used to generate the WXS file for Windows projects. It was fixed with the following PRs:\n\n* beeware/briefcase-windows-app-template#86\n* beeware/briefcase-windows-VisualStudio-template#85\n\nThese 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.\n\n### Workarounds\n\nThe change from beeware/briefcase-windows-app-template#86 can be added to any existing Briefcase .wxs file generated by Briefcase 0.3.24 or later.\n\n### Resources\n\nbeeware/briefcase#2759 is a formal bug report of the problem.","aliases":["CVE-2026-33430","PYSEC-2026-27"],"modified":"2026-06-05T14:30:11.172961403Z","published":"2026-03-23T21:40:10Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-03-23T21:40:10Z","nvd_published_at":"2026-03-26T17:16:38Z","cwe_ids":["CWE-732"],"severity":"HIGH"},"references":[{"type":"WEB","url":"https://github.com/beeware/briefcase/security/advisories/GHSA-r3r2-35v9-v238"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33430"},{"type":"WEB","url":"https://github.com/beeware/briefcase/issues/2759"},{"type":"WEB","url":"https://github.com/beeware/briefcase-windows-VisualStudio-template/pull/85"},{"type":"WEB","url":"https://github.com/beeware/briefcase-windows-app-template/pull/86"},{"type":"PACKAGE","url":"https://github.com/beeware/briefcase"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/briefcase/PYSEC-2026-27.yaml"}],"affected":[{"package":{"name":"briefcase","ecosystem":"PyPI","purl":"pkg:pypi/briefcase"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.3.0"},{"fixed":"0.3.26"}]}],"versions":["0.3.0","0.3.1","0.3.10","0.3.10rc7","0.3.10rc8","0.3.11","0.3.11rc4","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.18","0.3.19","0.3.2","0.3.20","0.3.21","0.3.22","0.3.23","0.3.24","0.3.25","0.3.26rc5","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-r3r2-35v9-v238/GHSA-r3r2-35v9-v238.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H"}]}