This update for xen fixes several issues. These security issues were fixed: - CVE-2018-3639: Prevent attackers with local user access from extracting information via a side-channel analysis, aka Speculative Store Bypass , Variant 4 . - CVE-2017-5753,CVE-2017-5715,CVE-2017-5754: Improved Spectre v2 mitigations . bsc#1027519