MSRC-CVE-2026-96303 — Microsoft PowerShell Security Feature Bypass Vulnerability

Summary

Impact: Security Feature Bypass. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.

Details

What kind of security feature could be bypassed by successfully exploiting this vulnerability?
An attacker who successfully exploited this vulnerability could bypass Windows Defender Application Control and PowerShell Constrained Language Mode restrictions, allowing untrusted code to run with capabilities those protections are designed to block.

Security updates
7.5.12 — https://github.com/PowerShell/Announcements/blob/main/pwsh/2026/10/CVE-2026-96303.md

Vulnerabilities 1

Medium 6.5

CVE-2026-96303

Microsoft PowerShell Security Feature Bypass Vulnerability

Improperly implemented security check for standard in Microsoft PowerShell allows an unauthorized attacker to bypass a security feature over a network.

Microsoft PowerShell 7.4 PowerShell 7.5 PowerShell 7.6 Alpine

Oct 13, 2026

Revision history

2026-10-22 #2
Corrected Fixed Build Number and Download links in the Security Updates table. This is an informational change only.
2026-10-13 #1
Information published.

References

CVE-2026-96303 Microsoft PowerShell Security Feature Bypass Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96303
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss