Race condition in Linux kernel - CVE-2026-64284
Published: July 27, 2026
Vulnerability identifier: #VU139696
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64284
CWE-ID: CWE-362
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause guest memory dirty logging to be incomplete.
The vulnerability exists due to improper synchronization in KVM x86 exit handling when processing fastpath userspace exits. A local user can trigger a fastpath userspace exit to cause guest memory dirty logging to be incomplete.
The issue affects vendor-specific KVM exit handling paths such as VMX, where operations needed before returning control to userspace may be skipped.
Affected software
Linux kernel
How to mitigate CVE-2026-64284
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3