CVE-2026-63937
High
Description
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.
SeverityHigh
CVSS8.8
Exploit probability—
Product
Linux Kernel
PublishedJul 19, 2026
First seenJul 19, 2026
Weakness typeCWE-367CWE-367
How to fix
Update
- linux linux_kernel6.12.93, 6.18.35, 7.0.12 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 6.11 ≤ v < 6.12.93, 6.13 ≤ v < 6.18.35, 6.19 ≤ v < 7.0.12, 7.1 | 6.12.93, 6.18.35, 7.0.12 |
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