An unprivileged domain can trigger an error path in the VIRQ_DOM_EXC binding logic that removes the bitmap Xenstore uses to track domain states, even when the bitmap is not initialized. This loss of state data causes Xenstore to provide inaccurate or missing domain information, leading to interruptions in management and monitoring services that rely on Xenstore. The flaw constitutes a boundary decision problem (CWE‑459) and results in a denial of service to Xenstore.

The vulnerability affects the Xen hypervisor’s Xenstore component. All Xen installations that implement the XEN_DOMCTL_get_domain_state control operation and VIRQ_DOM_EXC binding logic are potentially impacted; no specific version ranges are listed in the advisory.

The CVSS score of 7.5 indicates a high severity, while the EPSS score of <1% indicates a low probability of exploitation at this time. The flaw is not yet listed in the CISA KEV catalog. The likely attack vector is local: an unprivileged guest VM can issue a get domain state request to trigger the error path, which would disrupt Xenstore and any management tools that depend on accurate domain state data.