Multiple vulnerabilities have been discovered in the Xen hypervisor: CVE-2018-12891 It was discovered that insufficient validation of PV MMU operations may result in denial of service. CVE-2018-12892 It was discovered that libxl fails to honour the "readonly" flag on HVM-emulated SCSI disks. CVE-2018-12893 It was discovered that incorrect implementation of debug exception checks could result in denial of service.