Use-after-free in Linux kernel - CVE-2026-64562
Published: August 4, 2026
Vulnerability identifier: #VU140931
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-2026-64562
CWE-ID: CWE-416
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 a use-after-free in KVM nested VMX shadow VMCS handling when freeing nested virtualization state asynchronously with respect to loaded VMCS clearing during vCPU migration. A local user can trigger nested virtualization cleanup and vCPU migration to execute VMCLEAR on a freed shadow VMCS and cause a denial of service.
The issue occurs because vmcs01 may still reference the shadow VMCS until explicit VMCLEAR completes.
Affected software
Linux kernel
How to mitigate CVE-2026-64562
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/1dabef6e206568bf9d9ade74f6e56a48ea35695d
- https://git.kernel.org/stable/c/589419470030a89f16cf19300658b6dc644ca946
- https://git.kernel.org/stable/c/622ebfac01ba4f9c0060cebd41257fe46fc4a0b3
- https://git.kernel.org/stable/c/8001d2ce9d9bd09118ce523aef595aa094573ae3
- https://git.kernel.org/stable/c/af56298e9d86e6098cd1d2e155cb2949b7c45412