Improper access control in XenAPI Server - CVE-2026-23559
Published: April 29, 2026
Vulnerability identifier: #VU128446
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-23559
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Xen Project
Affected software:
XenAPI Server
XenAPI Server
Detailed vulnerability description
The vulnerability allows a remote user to read and modify arbitrary files in dom0.
The vulnerability exists due to improper access control in VBD.other_config:backend-local handling when configuring a virtual block device. A remote user can set the backend-local option to turn arbitrary files in dom0 into virtual disks and attach them to a VM they control to read and modify arbitrary files in dom0.
The vulnerability is exposed only when RBAC is configured for the pool.
How to mitigate CVE-2026-23559
Install security update from vendor's website.