CVE-2026-63938 PUBLISHED

KVM: SEV: Check PSC request indices against the actual size of the buffer

Assigner: Linux
Reserved: 19.07.2026 Published: 19.07.2026 Updated: 20.07.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS Score: 9.3

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 9b54e248d2644be71cb394eb85f31ad99e023a05 to 5198f70c09a5f6e9e5f5a0a2c6b388f24294b176 (excl.)
  • affected from 9b54e248d2644be71cb394eb85f31ad99e023a05 to 75c8d1d7291268b479794fba5808971dc2f5eaf3 (excl.)
  • affected from 9b54e248d2644be71cb394eb85f31ad99e023a05 to 505a3b94535583e4265360e2621734e355ef263d (excl.)
  • affected from 9b54e248d2644be71cb394eb85f31ad99e023a05 to 121d88de56bc5c0ba0ce2f6381af67f948a7e7c1 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.11 is affected
  • unaffected from 0 to 6.11 (excl.)
  • unaffected from 6.12.93 to 6.12.* (incl.)
  • unaffected from 6.18.35 to 6.18.* (incl.)
  • unaffected from 7.0.12 to 7.0.* (incl.)
  • unaffected from 7.1 to * (incl.)

References