CVE-2017-12136: Citrix Xenserver

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

Race condition in the grant table code in Xen 4.6.x through 4.9.x allows local guest OS administrators to cause a denial of service (free list corruption and host crash) or gain privileges on the host via vectors involving maptrack free list handling.

Affected products

• Citrix Xenserver: version 6.0.2 only; version 6.2.0 only; version 6.5 only; version 7.0 only; version 7.1 only; version 7.2 only
• Debian Debian Linux: version 8.0 only; version 9.0 only
• Xen Xen: version 4.6.0 only; version 4.6.1 only; version 4.6.3 only; version 4.6.4 only; version 4.6.5 only; version 4.6.6 only; …

Published 2017-08-24. Last modified 2026-06-17.