CVE Catalog

CVE-2026-64307

Low risk· EPSS 12%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.22%

12th percentile - higher than 12% of all known CVEs

Summary

In the Linux kernel's ccp (AMD) driver, a bug was fixed where SNP initialization was unnecessarily retried during the SNP_CONFIG ioctl. Now the operation is rejected if SNP was not previously initialized, preventing potential security issues.

Risk Assessment

Unnecessary retrying of SNP initialization could lead to clearing the HSAVE_PA register, risking host crash when attempting to run a virtual machine.

Recommendation

It is recommended to update the Linux kernel to a version containing the fix for CVE-2026-64307.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG) Sashiko notes: > if SEV initialization fails and KVM is actively running normal VMs, could a > userspace process trigger this code path via /dev/sev ioctls (e.g., > SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN > execution for an active VM trigger a general protection fault and crash the > host? Refuse to re-try initialization if SNP is not already initialized for SNP_CONFIG. This is technically an ABI break: before if SNP initialization failed it could be transparently retriggered by this ioctl, and if no VMs were running, everything worked fine. Hopefully this is enough of a corner case that nobody will notice, but someone does, there are a few options: * do something like symbol_get() for kvm and refuse to initialize if KVM is loaded * check each cpu's HSAVE_PA for non-zero data before re-initializing * once initialization has failed, continue to refuse to initialize until the ccp module is unloaded

Vulnerability data from NVD (NIST) · CISA KEV · EPSS