Improper Initialization in Linux kernel - CVE-2026-64561
Published: August 4, 2026
Vulnerability identifier: #VU140940
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64561
CWE-ID: CWE-665
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper state management in the KVM x86 shadow MMU page fault handling code when processing stale page faults after reclaiming shadow pages. A local user can trigger page faults that lead KVM to map memory into an invalid root to cause a denial of service.
The issue occurs when reclaiming shadow pages invalidates an in-use root, causing child shadow pages created during map or fetch operations to inherit an invalid role and violate the invariant that invalid shadow pages must not appear on the list of active MMU pages.
Affected software
Linux kernel
How to mitigate CVE-2026-64561
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/0026dbb7de8ea76e97d6edf42fc3cc084564e2bf
- https://git.kernel.org/stable/c/2abd5287f08319fa35764566b15c6e22cb1068db
- https://git.kernel.org/stable/c/35e77467610c4a37cb0ff54ee56b85f73b1f5700
- https://git.kernel.org/stable/c/bce0d3c26e2c761a4bf43c8949f333fc7374eb2d
- https://git.kernel.org/stable/c/f3477a6a4164f15287444eda685b5f6405dbd1e5