CVE-2026-63938
CriticalCVSS 9.3Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
A vulnerability was found in the Linux kernel's KVM component for AMD SEV. When processing Page State Change (PSC) requests, the PSC buffer indices were not validated against the actual scratch area size, potentially leading to an out-of-bounds read.
Risk Assessment
A malicious guest in a SEV-enabled virtual machine could exploit this vulnerability to read host kernel memory, potentially leading to privilege escalation or sensitive data leakage.
Recommendation
Apply the Linux kernel patch that validates PSC buffer indices immediately. Update to a kernel version containing this fix.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Check PSC request indices against the actual size of the buffer When processing Page State Change (PSC) requests, validate the PSC buffer against the effective size of the scratch area, which could be less than the maximum size if the guest provided a pointer that isn't exactly at the start of the GHCB shared buffer.