CVE-2026-63938 Details
Description
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.
A vulnerability in the Linux kernel's KVM SEV (Secure Encrypted Virtualization) implementation has been addressed. This issue involved improper validation of Page State Change (PSC) request indices against the actual size of the buffer. When processing PSC requests, the kernel did not adequately check the PSC buffer against the effective size of the scratch area, which could be smaller than expected if the guest provided a pointer that was not aligned with the beginning of the GHCB (Guest Hypervisor Communication Block) shared buffer. This flaw could potentially lead to buffer-related errors or vulnerabilities.
Users can upgrade to the latest stable version of the Linux kernel, where this vulnerability has been fixed. Instructions for downloading the patched version are available on the official Linux kernel website.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
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Weakness Enumeration
No weakness enumeration is available for this CVE.
Affected Products
No affected product data is available for this CVE.
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 20, 2026 | CVE Modified | kernel.org |
| Jul 19, 2026 | New CVE Received | kernel.org |