CVE-2026-63938
CRITICAL severity · CVSS 9.3 · Out-of-bounds read
9.3CVSS CRITICAL
Summary
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.
Impact & exploitability
Attack vectorLocal
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)0%
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Official patch: https://git.kernel.org/stable/c/121d88de56bc5c0ba0ce2f6381af67f948a7e7c1 ↗
Additional information
- NVD record
- https://git.kernel.org/stable/c/121d88de56bc5c0ba0ce2f6381af67f948a7e7c1Patch
- https://git.kernel.org/stable/c/505a3b94535583e4265360e2621734e355ef263dPatch
- https://git.kernel.org/stable/c/5198f70c09a5f6e9e5f5a0a2c6b388f24294b176Patch
- https://git.kernel.org/stable/c/75c8d1d7291268b479794fba5808971dc2f5eaf3Patch