CVE-2026-63937
KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer
CVSS Score
8.8
EPSS Score
0.0%
EPSS Percentile
0th
In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer Use READ_ONCE() when reading entries/indices from the guest-accessible Page State Change buffer to defend against TOCTOU bugs. Don't bother with READ_ONCE()/WRITE_ONCE() for cases where KVM is writing (and not consuming the result!), as the guest isn't supposed to touch the buffer while it's being processed. I.e. using READ_ONCE() is all about protecting against misbehaving guests.
| Vendor | linux |
| Product | linux |
| Ecosystems | |
| Industries | Technology |
| Published | Jul 19, 2026 |
| Last Updated | Aug 5, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
Linux / Linux
9b54e248d2644be71cb394eb85f31ad99e023a05 < bd232801ef1d1fd985d2d4ca3cd1d888303ca86f 9b54e248d2644be71cb394eb85f31ad99e023a05 < b1dfaa6f7a957726a6800135be3659fbe4bbf2a4 9b54e248d2644be71cb394eb85f31ad99e023a05 < edbbe88f83b524434974e84808d3093199d67c24 9b54e248d2644be71cb394eb85f31ad99e023a05 < c8cc238093ca6c99267032f6cfe78f59389f3157
Linux / Linux
6.11
References
git.kernel.org: https://git.kernel.org/stable/c/bd232801ef1d1fd985d2d4ca3cd1d888303ca86f git.kernel.org: https://git.kernel.org/stable/c/b1dfaa6f7a957726a6800135be3659fbe4bbf2a4 git.kernel.org: https://git.kernel.org/stable/c/edbbe88f83b524434974e84808d3093199d67c24 git.kernel.org: https://git.kernel.org/stable/c/c8cc238093ca6c99267032f6cfe78f59389f3157