VULNERABILITY INTELLIGENCE
CVE-2026-64284
CVSS score7.1 HIGH
EPSS probability0.13%
CISA KEVNot currently listed
Published2026-07-25
Last modified2026-10-19
CVSS vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits Move the handling of fastpath userspace exits into vendor code to ensure KVM runs vendor specific operations that need to run before userspace gains control of the vCPU. E.g. for VMX (and soon to be for SVM as well), KVM needs to flush the PML buffer prior to exiting to userspace, otherwise any memory written by the final KVM_RUN might never be flagged as dirty. Note, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in general, as that risks consuming stale state in a fastpath handler. That will be addressed in a future change.
Weakness classification
- CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
- CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition