Local privilege escalation via inherited MSI directory permissions
Published Mar 26, 2026 · Updated Mar 26, 2026
Incorrect directory permissions in BeeWare Briefcase before 0.3.26 allow local users to gain privileges through an All Users Windows MSI. The generated WXS template lets the installation directory inherit its parent DACL instead of protecting it and limiting built-in users to read and execute access. Exploitation requires a per-machine installation in an attacker-writable parent and an administrator who later launches a replaced application binary.
Summary
What happened
Incorrect directory permissions in BeeWare Briefcase before 0.3.26 allow local users to gain privileges through an All Users Windows MSI. The generated WXS template lets the installation directory inherit its parent DACL instead of protecting it and limiting built-in users to read and execute access. Exploitation requires a per-machine installation in an attacker-writable parent and an administrator who later launches a replaced application binary.
The record
- CVE
- CVE-2026-33430
- Published
- Mar 26, 2026
- Updated
- Mar 26, 2026
- Vendor
- BeeWare
- Product
- Briefcase
- Classifications
- CWE-732, T1574
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 26, 2026CVE publishedPublication date reported by the CVE source.
- Mar 26, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 0.3.0, < 0.3.26
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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