Xen through 4.8.x mishandles virtual interrupt injection, which allows guest OS users to cause a denial of service (hypervisor crash), aka XSA-223.

Xen through 4.8.x does not validate memory allocations during certain P2M operations, which allows guest OS users to obtain privileged host OS access, aka XSA-222.

Xen through 4.8.x does not validate the port numbers of polled event channel ports, which allows guest OS users to cause a denial of service (NULL pointer dereference and host OS crash) or possibly obtain sensitive information, aka XSA-221.

The vCPU context-switch implementation in Xen through 4.8.x improperly interacts with the Memory Protection Extensions (MPX) and Protection Key (PKU) features, which makes it easier for guest OS users to defeat ASLR and other protection mechanisms, aka XSA-220.

The shadow-paging feature in Xen through 4.8.x mismanages page references and consequently introduces a race condition, which allows guest OS users to obtain Xen privileges, aka XSA-219.

The grant-table feature in Xen through 4.8.x has a race condition leading to a double free, which allows guest OS users to cause a denial of service (memory consumption), or possibly obtain sensitive information or gain privileges, aka XSA-218 bug 2.

The grant-table feature in Xen through 4.8.x provides false mapping information in certain cases of concurrent unmap calls, which allows backend attackers to obtain sensitive information or gain privileges, aka XSA-218 bug 1.

Xen through 4.8.x mishandles page transfer, which allows guest OS users to obtain privileged host OS access, aka XSA-217.

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 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.

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.

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.

Xen through 4.8.x allows local 64-bit x86 HVM guest OS users to gain privileges by leveraging mishandling of SYSCALL singlestep during emulation.

The x86 segment base write emulation functionality in Xen 4.4.x through 4.7.x allows local x86 PV guest OS administrators to cause a denial of service (host crash) by leveraging lack of canonical address checks.

Xen 4.0.x through 4.7.x mishandle x86 task switches to VM86 mode, which allows local 32-bit x86 HVM guest OS users to gain privileges or cause a denial of service (guest OS crash) by leveraging a guest operating system that uses hardware task switching and allows a new task to start in VM86 mode.

Xen 4.7.x and earlier does not properly honor CR0.TS and CR0.EM, which allows local x86 HVM guest OS users to read or modify FPU, MMX, or XMM register state information belonging to arbitrary tasks on the guest by modifying an instruction while the hypervisor is preparing to emulate it.

Buffer overflow in Xen 4.7.x and earlier allows local x86 HVM guest OS administrators on guests running with shadow paging to cause a denial of service via a pagetable update.

The guest_walk_tables function in arch/x86/mm/guest_walk.c in Xen 4.6.x and earlier does not properly handle the Page Size (PS) page table entry bit at the L4 and L3 page table levels, which might allow local guest OS users to gain privileges via a crafted mapping of memory.

Buffer overflow in hw/pt-msi.c in Xen 4.6.x and earlier, when using the qemu-xen-traditional (aka qemu-dm) device model, allows local x86 HVM guest administrators to gain privileges by leveraging a system with access to a passed-through MSI-X capable physical PCI device and MSI-X table entries, related to a "write path."

Xen 4.6.x and earlier allows local guest administrators to cause a denial of service (host reboot) via vectors related to multiple mappings of MMIO pages with different cachability settings.