The grant-table feature in Xen through 4.8.x does not ensure sufficient type counts for a GNTMAP_device_map and GNTMAP_host_map mapping, which allows guest OS users to cause a denial of service (count mismanagement and memory corruption) or obtain privileged host OS access, aka XSA-224 bug 2.
The grant-table feature in Xen through 4.8.x mishandles MMIO region grant references, which allows guest OS users to cause a denial of service (loss of grant trackability), aka XSA-224 bug 3.
Xen through 4.6.x on 64-bit platforms mishandles a failsafe callback, which might allow PV guest OS users to execute arbitrary code on the host OS, aka XSA-215.
Xen 4.5.x through 4.7.x on AMD systems without the NRip feature, when emulating instructions that generate software interrupts, allows local HVM guest OS users to cause a denial of service (guest crash) by leveraging IDT entry miscalculation.
Xen 4.5.x through 4.7.x on AMD systems without the NRip feature, when emulating instructions that generate software interrupts, allows local HVM guest OS users to cause a denial of service (guest crash) by leveraging an incorrect choice for software interrupt delivery.
Xen through 4.8.x allows local x86 PV guest OS kernel administrators to cause a denial of service (host hang or crash) by modifying the instruction stream asynchronously while performing certain kernel operations.
VMFUNC emulation in Xen 4.6.x through 4.8.x on x86 systems using AMD virtualization extensions (aka SVM) allows local HVM guest OS users to cause a denial of service (hypervisor crash) by leveraging a missing NULL pointer check.
CMPXCHG8B emulation in Xen 3.3.x through 4.7.x on x86 systems allows local HVM guest OS users to obtain sensitive information from host stack memory via a "supposedly-ignored" operand size prefix.
The pygrub boot loader emulator in Xen, when S-expression output format is requested, allows local pygrub-using guest OS administrators to read or delete arbitrary files on the host via string quotes and S-expressions in the bootloader configuration file.