The x86 emulator in Xen 3.2.x through 4.5.x does not properly ignore segment overrides for instructions with register operands, which allows local guest users to obtain sensitive information, cause a denial of service (memory corruption), or possibly execute arbitrary code via unspecified vectors.
Exploitability
AV:LAC:LAu:NImpact
C:CI:CA:C7.2/AV:L/AC:L/Au:N/C:C/I:C/A:C