vm-admins can read/modify dom0 and access host hardware via XAPI, enabling full host compromise across virtual infrastructure.
CVE-2026-23559
XAPI vm-admin role allows dom0 file write and hardware access, enabling host compromise.
Is CVE-2026-23559 being exploited?
Not confirmed. CVE-2026-23559 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.17% probability of exploitation in the next 30 days.
How severe is CVE-2026-23559?
CVE-2026-23559 is rated Critical with a CVSS score of 9.4. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-23559?
Yes. A fix has been recorded for CVE-2026-23559. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-23559 affect?
CVE-2026-23559 affects XAPI-managed Xen hosts (XenServer, XCP-ng), XenCenter/XAPI clients, Management tooling using XAPI. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-23559?
Remove/restrict vm-admin privileges, audit accounts/sessions, isolate affected hosts; apply vendor patch when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
A vm-admin can read/modify arbitrary dom0 files, write to dom0, access PCI passthrough, and escalate to host-level compromise/VM escape.
Immediate action required