CVE-2026-110111: Xen Orchestra before 6.9.0 Privilege Escalation via Prototype Pollution in vm.importFromEsxi
Xen Orchestra before 6.9.0 contains an improper access control vulnerability that allows any authenticated user to become global administrator by abusing the unprotected vm.importFromEsxi and vm.importMultipleFromEsxi methods. Attackers can point xo-server at a malicious ESXi host serving a crafted .vmx file with proto.permission set, polluting Object.prototype so permission-less accounts inherit admin rights and enabling remote code execution.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Xen Orchestrato a version that resolves this vulnerability.Fixed in 6.9.0
Event History
Frequently Asked Questions
Which accounts are exposed to this issue?
Any authenticated Xen Orchestra user is potentially exposed because the affected import methods do not enforce the required access control. An account without existing permissions can inherit global administrator rights after successful exploitation.
What does an attacker need to exploit it?
The attacker needs an authenticated Xen Orchestra account and the ability to direct xo-server to a malicious ESXi host. That host must serve a crafted .vmx file containing a __proto__.permission value.
Is user interaction required?
No user interaction is required. The attacker invokes the affected vm.importFromEsxi or vm.importMultipleFromEsxi functionality after authenticating.
What is the impact after exploitation?
Successful exploitation can grant global administrator privileges to a permission-less account. The vulnerability description also states that this can enable remote code execution.
What version addresses the issue?
The issue affects Xen Orchestra versions before 6.9.0. Upgrading to version 6.9.0 or later removes the stated affected version range.