Improper Input Validation in Microsoft PowerShell Allows Unauthorized Security Feature Bypass

Last refreshed2026-09-26

Status: NEW | Advisory ID: CVE-2026-26143

Key Details

CVE	CVE-2026-26143
CVSS Score / Version	7.8 (High) / CVSS v3.1
Updated	2026-09-24
CVSS Vector	`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`
CVSS Prose	attack vector is local; attack complexity is low; privileges required is none; user interaction is required; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high.
Classified as	CWE-20 (Improper Input Validation)

Improper input validation in Microsoft PowerShell allows an unauthorized attacker to bypass a security feature locally.

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-26143
CVE	https://www.cve.org/CVERecord?id=CVE-2026-26143
Vendor advisory	https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26143

Source

Reference

NVD

CVE

Vendor advisory