Critical severity · published Jul 19, 2026
CVE-2026-63938
KVM: SEV: Check PSC request indices against the actual size of the buffer
9.3
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 9% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
6.11 before 6.12.93; 6.13 before 6.18.35; 6.19 before 7.0.12; 7.1; 7.1; 7.1; +2 more · source: NVD
LI
Linux · Linux
9b54e248d2644be71cb394eb85f31ad99e023a05 before 5198f70c09a5f6e9e5f5a0a2c6b388f24294b176; 9b54e248d2644be71cb394eb85f31ad99e023a05 before 75c8d1d7291268b479794fba5808971dc2f5eaf3; 9b54e248d2644be71cb394eb85f31ad99e023a05 before 505a3b94535583e4265360e2621734e355ef263d; 9b54e248d2644be71cb394eb85f31ad99e023a05 before 121d88de56bc5c0ba0ce2f6381af67f948a7e7c1; 6.11 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-63938
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-63938
Patch
https://git.kernel.org/stable/c/121d88de56bc5c0ba0ce2f6381af67f948a7e7c1
Patch
https://git.kernel.org/stable/c/505a3b94535583e4265360e2621734e355ef263d
Patch
https://git.kernel.org/stable/c/5198f70c09a5f6e9e5f5a0a2c6b388f24294b176
Patch
https://git.kernel.org/stable/c/75c8d1d7291268b479794fba5808971dc2f5eaf3
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