CVE-2026-64285

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the KVM SEV implementation when populating a guest memfd instance with initial CPUID data for an SNP guest. KVM may write back corrected CPUID information if the data provided by userspace is rejected by trusted firmware. Because this write operation uses a kernel mapping, pinning the source page for read-only access instead of write access can lead to KVM overwriting read-only memory. This is less likely to affect well-behaved Virtual Machine Monitors (VMMs) since CPUID information is typically dynamically generated by userspace and rarely backed by read-only mappings.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.