CVE-2026-40400 Windows PowerShell Remote Code Execution Vulnerability
An authorized attacker can execute code over a network via relative path traversal in Windows PowerShell.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-40400?
CVE-2026-40400 is a high-severity path traversal vulnerability in Microsoft Windows 10 1607, published on 14 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Relative path traversal in Windows PowerShell allows an authorized attacker to execute code over a network.
Weakness: CWE-23
Which versions are affected by CVE-2026-40400?
It affects 12 products.
Products include Microsoft Windows 10 1607, Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2 and 6 more.
How do I fix CVE-2026-40400?
No fix has been published for CVE-2026-40400 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-40400 being exploited?
There is no known exploitation of CVE-2026-40400 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Windows 10 1607
- CVE-2026-33824 Microsoft Internet Key Exchange (IKE) Service Extensions Double Free
- CVE-2026-21510 Microsoft Windows Shell Protection Mechanism Failure
- CVE-2026-21513 Microsoft MSHTML Framework Protection Mechanism Failure
- CVE-2023-32049 Microsoft Windows Defender SmartScreen Security Feature Bypass
- CVE-2023-29360 Microsoft Streaming Service Untrusted Pointer Dereference
Sources
Also known as GHSA-wvqj-vj23-9cf7.