CVE-2026-64307

A flaw was found in the Linux kernel's crypto:ccp module. A local attacker with access to a userspace process could exploit this vulnerability. If Secure Encrypted Virtualization (SEV) initialization fails while Kernel-based Virtual Machine (KVM) is running virtual machines, the attacker can trigger a specific code path through /dev/sev input/output controls (ioctls). This can cause a system crash, leading to a Denial of Service (DoS) for the host.

A local SEV device ioctl path can retry SNP initialization through SNP_CONFIG when SNP is not already initialized. If SEV or SNP initialization previously failed while KVM is running normal VMs, this can disturb global SEV state such as MSR_VM_HSAVE_PA and make a later VMRUN fault in the host. For the CVSS the PR:L is used for the paranoid score because writable access to /dev/sev may be delegated to a virtualization service account, group, or reduced capability root in some deployments. The issue is not network reachable and requires local access to the SEV control device. Impact is denial of service of the host through a crash or fatal fault in the virtualization path. No direct confidentiality or integrity primitive is visible from the patch, so the impact is kept as C:N/I:N/A:H.

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.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.