Microsoft PowerShell Help Directory Traversal Remote Code Execution Vulnerability
Vulnerability Details
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft PowerShell. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the parsing of PowerShell module help files. The issue results from the lack of proper validation of a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to execute code in the context of the current user.
Additional Details
Microsoft has issued an update to correct this vulnerability. More details can be found at:
https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-40400
Disclosure Timeline
- 2026-05-28 - Vulnerability reported to vendor
- 2026-07-15 - Coordinated public release of advisory
- 2026-07-15 - Advisory Updated
Credit
Richard Chen of TrendAI Research
