CVE-2026-68081: KVM: nVMX: Put vmcs12 pages if nested VM-Enter fails due to invalid guest state

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-08 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Put vmcs12 pages if nested VM-Enter fails due to invalid guest state Put all vmcs12 pages if KVM synthesizes a nested VM-Exit due to invalid guest while emulating VMLAUNCH or VMRESUME. The invalid guest state path doesn't use nested_vmx_vmexit() as that API is intended to be used if and only if L2 is active, and the open coded equivalent neglects to put the vmcs12 pages. Failure to put the vmcs12 pages leaks any pinned pages (and/or mappings) if L1 retries VMLAUNCH/VMRESUME. Note, the !from_vmenter scenario doesn't suffer the same problem, as vmx_get_nested_state_pages() only gets/pins/maps the vmcs12 pages if L2 is active, i.e. if a "full" VM-Exit is guaranteed before KVM will retry getting vmcs12 pages.

Affected products

Linux: 5.2 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux 7.2. Check the vendor advisory for mitigations.

References

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