A malicious 64-bit PV guest may be able to access all of system memory, allowing for all of privilege escalation, host crashes, and information leaks by placing a IRET hypercall in the middle of a multicall batch (XSA-213, bsc#1034843)
A malicious pair of guests may be able to access all of system memory, allowing for all of privilege escalation, host crashes, and information leaks because of a missing check when transfering pages via GNTTABOP_transfer (XSA-214, bsc#1034844).
CVE-2017-7718: hw/display/cirrusvgarop.h allowed local guest OS privileged users to cause a denial of service (out-of-bounds read and QEMU process crash) via vectors related to copying VGA data via the cirrusbitbltropfwdtransp_ and cirrusbitbltropfwd functions (bsc#1034994).
CVE-2016-9603: A privileged user within the guest VM could have caused a heap overflow in the device model process, potentially escalating their privileges to that of the device model process (bsc#1028655)
These non-security issues were fixed:
bsc#1029827: Additional xenstore patch
bsc#1036146: Xen VM dumped core to wrong path
bsc#1022703: Prevent Xen HVM guest with OVMF to hang with unattached CDRom