CVE-2026-31593

A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) virtualization module. When Secure Nested Paging (SNP) is enabled, an attempt to update the state of an already running and encrypted virtual machine can cause the host system to crash. This vulnerability leads to a Denial of Service (DoS) for the host, making the system unavailable.

Upstream rejects illegal attempts to sync VMSA for vCPUs already launched under SNP, preventing inconsistent encrypted state. Red Hat concurs with AMD KVM hardening guidance: apply kernel updates on SNP systems.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.