An issue (known as XSA-212) was discovered in Xen, with fixes available for 4.8.x, 4.7.x, 4.6.x, 4.5.x, and 4.4.x. The earlier XSA-29 fix introduced an insufficient check on XENMEM_exchange input, allowing the caller to drive hypervisor memory accesses outside of the guest provided input/output arrays.
Severity
CVSS 3.0
8.2 high
CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
EPSS
1.6% chance of exploitation in the next 30 days; higher than 75% of CVEs (scores of 2026-10-31)