An out-of-bounds write in PowerShell 7 allows an unauthorized attacker to elevate privileges over a network.
System administrators are advised to update PowerShell 7 to an unaffected version (see affected software ).
Please open a support question to the PowerShell aspects of this advisory.
This issue affects you if you use Invoke-WebRequest or Invoke-RestMethod against websites without SSL or that you do not control.
The vulnerability affects PowerShell 7 prior to the following versions:
The vulnerability affects PowerShell when running on the following operating systems:
How do I know if I am affected?
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
Reporting Security Issues
If you have found a potential security issue in PowerShell 7, please email details to [email protected] .
You can ask questions this issue on GitHub in the PowerShell organization. This is located at . The Announcements repo ( ) will contain this bulletin as an issue and will include a link to a discussion issue where you can ask questions.
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 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.
Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure.
See acknowledgments for more information.
V1.0 (October 25, 2026): Advisory published.
Version 1.0 Last Updated 2026-10-25
The full story
This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.
