An uninitialized MMU pointer reset failure in the KVM nested‑virtualization code leads to a null pointer dereference when a guest attempts to load level‑2 state that fails outside a VM‑Entry. The kernel attempts to access a freed nested pointer, resulting in a kernel panic that crashes the host and all active virtual machines. This manifests as a denial of service to the host and its guests.

The flaw targets the Linux kernel’s KVM subsystem on Intel hosts, specifically the kvm_intel module when nested virtualization is enabled. Any distribution that includes the standard kernel KVM implementation on Intel hardware is vulnerable if it has not applied the patch that resets the MMU pointer on failure. The advisory provides no specific version numbers, so all kernels built before the fix are potentially affected.

There’s no published CVSS score and the EPSS score is unavailable; it is not listed in the CISA KEV catalog. Based on the description, it is inferred that an attacker would need to run privileged code inside a guest that triggers the L2 state load failure, such as by invoking RSM or KVM_SET_NESTED_STATE. While the lack of documented exploitation evidence suggests the immediate threat is moderate, any untrusted guest could cause a host crash if the flaw is triggered.