The xrstor function in arch/x86/xstate.c in Xen 4.x does not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allows local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits. NOTE: this vulnerability exists because of an incorrect fix for CVE-2013-2076.
Severity
CVSS 3.0
3.8 low
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
EPSS
0.4% chance of exploitation in the next 30 days; higher than 35% of CVEs (scores of 2026-10-31)