What Customers Should Do  

We have pushed updates to both the Early Access and Normal update channels of each of XenServer 8.4 and XenServer 9.  We recommend that customers update to the latest version from their chosen channel following the instructions at https://docs.xenserver.com/us/en/xenserver/8/update.html or https://docs.xenserver.com/us/en/xenserver/9/update.html   

Customers who wish to rotate the Pool Secret should follow the instructions at https://docs.xenserver.com/us/en/xenserver/8/hosts-pools/manage-pools.html#rotate-the-pool-secret or https://docs.xenserver.com/us/en/xenserver/9/hosts-pools/manage-pools.html#rotate-the-pool-secret  

What Citrix is 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/support-home/topic-article-list?trendingCategory=20&trendingTopicName=Security%20Bulletin  

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 

Subscribe to Receive Alerts  

Citrix strongly recommends that all customers subscribe to receive alerts when a security bulletin is created or modified at https://support.citrix.com/wolken-support/view/aboutsupport/my-support-alerts  

Reporting Security Vulnerabilities to Citrix 

Citrix welcomes input regarding the security of its products and considers any and all potential vulnerabilities seriously. For details on our vulnerability response process and guidance on how to report security-related issues to Citrix, please see the following webpage: https://www.cloud.com/trust-center/support   

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: High 

Description of Problem  

An issue has been identified that may allow an unauthenticated attacker on the management network to eventually infer the Pool Secret and so compromise the host.   

This issue has the following identifier: 

• CVE-2026-102705 

Several further issues have been identified that may allow 

1. an already authenticated host administrator with a Pool Operator, VM Power Administrator or VM Administrator role to escalate their privilege to that of a Pool Administrator role
2. an already authenticated host administrator with any role to terminate running tasks belonging to other roles. 

These issues have the following identifiers: 

• CVE-2026-102706 

• CVE-2026-102707 

• CVE-2026-102708 

• CVE-2026-119779 

• CVE-2026-119780 

In addition, AMD has disclosed several security issues affecting AMD CPUs.   Although these are not vulnerabilities in the XenServer product itself, for the convenience of customers we are providing updates that contain updated AMD microcode and corresponding product code changes to mitigate these CPU hardware issues.  Hosts that do not contain AMD CPUs are not affected by these CPU issues. 

The first of these issues may, under certain circumstances, allow a guest VM to compromise the host.  Further details may be found at https://www.amd.com/en/resources/product-security/bulletin/amd-sb-3060.html. 

This issue has the following identifier: 

• CVE-2024-21963 

The remaining CPU hardware issues may allow code in a guest VM to infer some active memory content of another VM that is running on the same host.  Hosts that do not contain AMD Zen5 CPUs are not affected by these remaining CPU issues.  

These issues have the following identifiers: 

• CVE-2024-36350 

• CVE-2024-36357 

• CVE-2026-0004 

Affected Versions  

These issues affect both XenServer 8.4 and XenServer 9.