CVE-2026-63937
In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer
CVSS
8.8
High
EPSS
0.2%
p6
KEV
—
Exploit Today
2
0-100
Published: Jul 19, 2026 · Last modified: Jul 27, 2026
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.
- git.kernel.orghttps://git.kernel.org/stable/c/b1dfaa6f7a957726a6800135be3659fbe4bbf2a4
- git.kernel.orghttps://git.kernel.org/stable/c/bd232801ef1d1fd985d2d4ca3cd1d888303ca86f
- git.kernel.orghttps://git.kernel.org/stable/c/c8cc238093ca6c99267032f6cfe78f59389f3157
- git.kernel.orghttps://git.kernel.org/stable/c/edbbe88f83b524434974e84808d3093199d67c24
No related CVEs by CWE or product.