High severity · published Jul 14, 2026
CVE-2026-40400
Windows PowerShell Remote Code Execution Vulnerability
8.0
CVSS
0.9%
EPSS
No
On KEV
Description
Relative path traversal in Windows PowerShell allows an authorized attacker to execute code over a network.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.9% · higher than 59% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
P7
PowerShell 7.5 · Microsoft
7.5.0 before 7.5.11 · source: vendor
P7
PowerShell 7.6 · Microsoft
7.6.0 before 7.6.6 · source: vendor
W1
Windows 10 Version 1607 · Microsoft
10.0.14393.0 before 10.0.14393.9339 · source: vendor
W1
Windows 10 Version 1809 · Microsoft
10.0.17763.0 before 10.0.17763.9020 · source: vendor
W1
Windows 10 Version 21H2 · Microsoft
10.0.19044.0 before 10.0.19044.7548 · source: vendor
W1
Windows 10 Version 22H2 · Microsoft
10.0.19045.0 before 10.0.19045.7548 · source: vendor
W1
Windows 11 Version 24H2 · Microsoft
10.0.26100.0 before 10.0.26100.8875 · source: vendor
W1
Windows 11 Version 25H2 · Microsoft
10.0.26200.0 before 10.0.26200.8875 · source: vendor
W1
Windows 11 version 26H1 · Microsoft
10.0.28000.0 before 10.0.28000.2525 · source: vendor
WS
Windows Server 2012 · Microsoft
6.2.9200.0 before 6.2.9200.26226 · source: vendor, NVD
WS
Windows Server 2012 (Server Core installation) · Microsoft
6.2.9200.0 before 6.2.9200.26226 · source: vendor
WS
Windows Server 2012 R2 · Microsoft
6.3.9600.0 before 6.3.9600.23291 · source: vendor
In the news
VulnerabilityHigh
ZDI-26-414: Microsoft PowerShell Help Directory Traversal Remote Code Execution Vulnerability
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 ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2026-40400.
Jul 15, 2026·Zero Day Initiative
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40400
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-40400
vendor-advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40400
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