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VSA-2026-012: Vulnerability in XCP-ng Windows Guest Tools

PublishedUpdatedSeverityCVSS 4.0Affected products
XXXX-XX-XXXXXX-XX-XX🟢 LowNot available yet- XCP-ng Windows Guest Tools
info

A vulnerability was discovered in XenClean/XenBootFix that are part of the XCP-ng Windows Guest Tools. We classify the impact as Low. For details on how we assign severity levels, see our Severity Levels Explained page.

Summary​

We recently discovered a vulnerability affecting the XCP-ng Windows Guest Tools. The vulnerability allows a malicious DLL located in the same directory as XenClean and XenBootFix to hijack its execution and execute untrusted code.

Impact​

The impact is execution of untrusted code. As the XenClean/XenBootFix processes run with Administrator privileges, the impact can include local privilege escalation.

Affected Versions​

  • XCP-ng Windows Guest Tools: XenClean/XenBootFix versions 9.1.148 and below.

Mitigation​

Do not use any affected versions of XenClean or XenBootFix.

If your VM is running XCP-ng Windows Guest Tools 9.1.146, you don't need to update. You just need to replace any XenClean and XenBootFix files you downloaded.

Resolution​

Users are recommended to only use the latest XenClean and XenBootFix versions from https://github.com/xcp-ng/win-pv-drivers/releases.

List of packages fixing these issues:

  • XCP-ng Windows Guest Tools: version 9.1.152 or later
  • XCP-ng 8.3:
    • xcp-ng-pv-tools version 8.3-17 or later

Credits​

Discovered and fixed by Tu Dinh of Vates.

References​

No CVE assigned yet.