During an intra‑host migration of a KVM guest that utilizes SEV, the Linux kernel does not issue cache maintenance on the source virtual machine after it is converted to a non‑SEV guest. This omission can leave sensitive data in host CPU caches that were encrypted for the guest, and an attacker could potentially read those stale cache lines. The weakness is a missing cache‑flush step that allows privacy disclosure.

The defect is present in all Linux kernels that include KVM SEV migration code and have not been patched to add cache maintenance on the source VM during migration. No specific kernel version range is listed, so any distribution shipping an unpatched kernel that contains the SEV migration code is potentially affected.

The CVSS score of 7.1 and an EPSS score < 1% indicate high severity and a low likelihood of exploitation yet. The vulnerability is not listed in CISA KEV, suggesting no publicly known exploits. The attack requires a privileged host operator or an attacker able to co‑locate a malicious guest and trigger a migration, as inferred from the description. The risk is primarily to data confidentiality for sensitive information that may have been cached during the VM’s execution.