CVE-2026-42486
VM-admin can write arbitrary files in dom0 via VM.platform:hvm_serial RBAC bug.
Is CVE-2026-42486 being exploited?
Not confirmed. CVE-2026-42486 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-2026-42486?
CVE-2026-42486 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-2026-42486?
Yes. A fix has been recorded for CVE-2026-42486. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-42486 affect?
CVE-2026-42486 affects XAPI (XenServer/XCP-ng), XenServer hosts (dom0), XAPI-managed VMs. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-42486?
Restrict/revoke vm-admin roles immediately; apply vendor patch when available and audit hosts.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
A vm-admin can write arbitrary files in dom0 via hvm_serial, enabling host/root compromise, code execution, and full host/VM control.
Immediate action required