CVE-2017-17563: Xen

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

An issue was discovered in Xen through 4.9.x allowing guest OS users to cause a denial of service (host OS crash) or gain host OS privileges by leveraging an incorrect mask for reference-count overflow checking in shadow mode.

Affected products

• Xen Xen: up to and including 4.9.1

Published 2017-12-12. Last modified 2026-06-17.