CVE-2026-63937

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the KVM SEV component where entries and indices are read from the guest-accessible Page State Change (PSC) buffer without proper synchronization. This lack of synchronization can lead to Time-of-Check to Time-of-Use (TOCTOU) bugs, which occur when a program checks a condition and then uses the result, but the condition changes between the check and the use. In this case, a misbehaving guest could modify the buffer while the kernel is processing it.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.