XAPI vulnerabilities

CVE-2026-42486 in XAPI allows a vm-admin user to set the VM.platform:hvm_serial parameter, which should be restricted to the pool-admin role. This enables arbitrary file write in dom0, potentially leading to privilege escalation and system compromise.

CVE-2026-23562 in XAPI (XenServer API) allows a vm-admin user to configure PCI passthrough, which is normally restricted to the pool-admin role. A missing permission check in one API grants unintended access to host hardware.

In XAPI, a user with the vm-admin role can set the VM.other_config:storage_driver_domain parameter, marking a VM as the storage domain for a PBD connection. Shutting down such a VM may cause the PBD to be erroneously marked as unplugged when it is not.

Vulnerability CVE-2026-23560 in XAPI allows a vm-admin user to set the VM.other-config:is_system_domain parameter, marking a virtual machine as a system domain. Such domains are ignored and left running during host or pool operations, and may be hidden from administrative tools.

A user with the vm-admin role in XAPI can set the VBD.other_config:backend-local parameter, allowing arbitrary files in dom0 to be turned into virtual disks (VDIs) and attached to a controlled VM. This enables unauthorized read and modification of files in dom0.

Multiple issues exist in XAPI: (1) database updates sanitize input strings but generate notifications from unsanitized input, causing the database event thread to terminate; (2) XAPI's UTF-8 encoder implements Unicode v3.0 while libraries use v3.1, leading to acceptance of invalid strings that can prevent database loading; (3) no input sanitization for Map/Set updates on database objects.