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 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.

CVSS 3.1

8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS

0.1% chance of exploitation in the next 30 days; higher than 2% of CVEs (scores of 2026-10-25)

CWE

CWE-367

Published

2026-07-19

Modified

2026-10-19

Record from

the NVD, synced 2026-10-21

References

• https://git.kernel.org/stable/c/b1dfaa6f7a957726a6800135be3659fbe4bbf2a4
• https://git.kernel.org/stable/c/bd232801ef1d1fd985d2d4ca3cd1d888303ca86f
• https://git.kernel.org/stable/c/c8cc238093ca6c99267032f6cfe78f59389f3157
• https://git.kernel.org/stable/c/edbbe88f83b524434974e84808d3093199d67c24

Check your stackJSON