CVE-2026-33430: beeware briefcase · Incorrect Permissions
Affects beeware briefcaseSource CVE Database V5
Not known to be exploited · CVSS 7.3 High : upgrade to 0.3.26 soon.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.3.26
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 26 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade beeware briefcase to 0.3.26.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| beewarebriefcase | Affected
| Fixed in
|
PyPIbriefcasepkg:pypi/briefcaseOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in beeware briefcase versions 0.3.26, 0.4.0, and 0.4.1, which include updated WXS templates correcting the permission assignment issue. Users should upgrade to one of these versions and re-run `briefcase create` to regenerate the installer templates. For existing WXS files generated by briefcase 0.3.24 or later, the patch can be manually applied to correct the permissions. No vendor advisory was provided, so check the official beeware documentation or repository for the patch details and instructions.
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.
References
- github.com/beeware/briefcase/security/advisories/GHSA-r3r2-35v9-v238 (opens in a new tab)
- github.com/beeware/briefcase/issues/2759 (opens in a new tab)
- github.com/beeware/briefcase-windows-VisualStudio-template/pull/85 (opens in a new tab)
- github.com/beeware/briefcase-windows-app-template/pull/86 (opens in a new tab)