https://seclists.org/oss-sec/2026/q4/142: Xen Security Advisory 514 v2 (CVE-2026-79607) - XenstoGuests can crash xenstod during Live Update
Published Oct 13, 2026
·Updated
Affected Software
1 affected component
XEN Xen=4.22
Only Xen 4.22 systems using the C Xenstore implementation are vulnerable, whether it runs as a daemon or as a stubdom. Xen 4.21 and older are not vulnerable, and oxenstored is not affected.
An unprivileged guest can trigger the issue during a Xenstore live update. The flaw involves Xenstore watches configured with a specified watch depth.
The Xenstore service can crash or its data can become corrupted during the live update. This can prevent further domain administration actions on the host.
Avoid performing Xenstore live updates, which avoids the vulnerable code path. Switching from the C Xenstore implementation to oxenstored also avoids the vulnerability.