Microsoft Security Advisory: PowerShell Defense in Depth Updates

Executive Summary

An issue exists in PowerShell that could lead to unauthorized command access that is being addressed by defense-in-depth measures in PowerShell 7.

System administrators are advised to update PowerShell 7 to an unaffected version (see affected software).

Discussion

Please open a support question to discuss the PowerShell aspects of this advisory.

Mitigation factors

The following mitigating factors might be helpful in your situation. This issue does not affect you:

• If you deploy App Control for Business with script in enforcement mode.
• If you do not deploy AppLocker script rules in enforcement mode.

Affected Software

The vulnerability affects PowerShell 7 prior to the following versions:

The vulnerability affects PowerShell when running on the following operating systems:

Advisory FAQ

How do I know if I am affected?

If all of the following are true:

1. Run pwsh -v, then, check the version in the table in Affected Software to see if your version of PowerShell 7 is affected.

How do I update to an unaffected version?

Follow the instructions at Installing PowerShell 7 to install the latest version of PowerShell 7.

Updating PowerShell 7 using Microsoft Update

Updating PowerShell 7 using Microsoft Update

Other Information

Reporting Security Issues

If you have found a potential security issue in PowerShell 7,
please email details to secure@microsoft.com.

Support

You can ask questions about this issue on GitHub in the PowerShell organization.
This is located at https://github.com/PowerShell/.
The Announcements repo (https://github.com/PowerShell/Announcements)
will contain this bulletin as an issue and will include a link to a discussion issue where you can ask questions.

Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

What if the update breaks my script or module?

You can uninstall the newer version of PowerShell 7 and install the previous version of PowerShell 7.
This should be treated as a temporary measure.
Therefore, the script or module should be updated to work with the patched version of PowerShell 7.

Acknowledgments

• Aaron Margosis

Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure.

See acknowledgments for more information.

Revisions

V1.1 (May 15, 2025): Added acknowledgment.

V1.0 (May 15, 2025): Advisory published.

Version 1.1
Last Updated 2023-05-15