Critical 9.3Published Jul 19, 2026

CVE-2026-63938KVM: SEV: Check PSC request indices against the actual size of the buffer

Updated under an hour ago (Oct 28, 2026, 7:10 PM ET)

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Exploited in the last 30 days

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.

CVSS: 9.3 CRITICAL (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-125
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 9b54e248d2644be71cb394eb85f31ad99e023a05 before 5198f70c09a5f6e9e5f5a0a2c6b388f24294b176; from 9b54e248d2644be71cb394eb85f31ad99e023a05 before 75c8d1d7291268b479794fba5808971dc2f5eaf3; from 9b54e248d2644be71cb394eb85f31ad99e023a05 before 505a3b94535583e4265360e2621734e355ef263d; from 9b54e248d2644be71cb394eb85f31ad99e023a05 before 121d88de56bc5c0ba0ce2f6381af67f948a7e7c1	CNA record
linux linux_kernel linux:linux_kernel	from 6.11 before 6.12.93; from 6.13 before 6.18.35; from 6.19 before 7.0.12; 7.1; 7.1; 7.1; 7.1; 7.1	NVD

References

References

https://git.kernel.org/stable/c/5198f70c09a5f6e9e5f5a0a2c6b388f24294b176	patch
https://git.kernel.org/stable/c/75c8d1d7291268b479794fba5808971dc2f5eaf3	patch
https://git.kernel.org/stable/c/505a3b94535583e4265360e2621734e355ef263d	patch
https://git.kernel.org/stable/c/121d88de56bc5c0ba0ce2f6381af67f948a7e7c1	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.