What Customers Should Do

We have released updated versions of both XenCenter and the SDK.  We recommend that customers update their existing XenCenter to the latest version using the built-in update functionality as documented at https://docs.xenserver.com/en-us/xencenter/current-release/updates-xencenter.html 

We recommend that customers using the SDK download the latest version from https://www.xenserver.com/downloads   

What We Are Doing 

We are notifying customers and channel partners about this potential security issue through the publication of this security bulletin on the Citrix Knowledge Center at https://support.citrix.com/securitybulletins  

Acknowledgement

Cloud Software Group thanks the Veeam Team for working with us to protect our customers. 

Obtaining Support on This Issue

If you require technical assistance with this issue, please contact Citrix Technical Support. Contact details for Citrix Technical Support are available at https://www.citrix.com/support 

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Reporting Security Vulnerabilities to Us

We welcome input regarding the security of our products and consider any and all potential vulnerabilities seriously. For details on our vulnerability response process and guidance on how to report security-related issues to us, please see the following webpage: https://www.citrix.com/about/trust-center/vulnerability-process.html 

Change Log

The information on this page is being provided to you on an "AS IS" and "AS-AVAILABLE" basis. The issues described on this page may or may not impact your system(s). Cloud Software Group, Inc. and its subsidiaries (collectively, "Cloud SG") make no representations, warranties, or guarantees as to the information contained herein. ANY AND ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, WITHOUT LIMITATION, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT AND FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. BY ACCESSING THIS PAGE, YOU ACKNOWLEDGE THAT CLOUD SG SHALL IN NO EVENT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES THAT ARISE OUT OF YOUR USE OR FAILURE TO USE THE INFORMATION CONTAINED HEREIN. Cloud SG reserves the right to change or update the information on this page at any time. We accordingly recommend that you always view the latest version of this page. The information contained herein is being provided to you under the terms of your applicable customer agreement with Cloud SG, and may be used only for the purposes contemplated by such agreement. If you do not have such an agreement with Cloud SG, this information is provided under the cloud.com Terms of Use, and may be used only for the purposes contemplated by such Terms of Use.

Severity: Medium

Description of Problem

An issue has been identified in the XenServer management API SDK that may allow an attacker on the management network who is able to intercept specific HTTPS requests within a higher-level operation to be able to act with the privileges of the intercepted administrator.  This issue affects the XenCenter management agent together with third-party PowerShell and C# SDK clients.

This issue has the following identifier:

• CVE-2026-42491 

Affected Versions

This issue affects XenCenter versions before 2026.4.0 and, for PowerShell and C# clients only, SDK versions before 26.15.0.  As the issue is in the client-side (XenCenter and SDK) code, it is independent of the version of XenServer that is in use.