Live › vulnerability › CVE-2026-98863
Go to dashboardWhen KVM fails to map a nested guest's pages before returning to userspace, the request to retry is not re-queued, so a rerun of the vCPU can re-enter the guest with stale, unpinned host page frames mapped into its virtual APIC page. The sources do not describe a confirmed exploit path or attacker capability beyond this memory-safety consequence.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Hosts running Linux with KVM on x86 that use nested virtualization (guests that run their own hypervisor) are the relevant systems. Hosts without KVM or without nested virtualization enabled are unlikely to be exposed, but the sources do not state this explicitly.
No product ranges from the sources yet.
uname -r and compare against the fixed kernel versions in the upstream commit referenced by the NVD entrycat /sys/module/kvm_intel/parameters/nested or cat /sys/module/kvm_amd/parameters/nestedEach row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Re-pend GET_NESTED_STATE_PAGES if getting said pages fails
Re-pend GET_NESTED_STATE_PAGES before exiting to userspace if getting the nested pages fails in the KVM_RUN path. If userspace re-runs the vCPU, and vmcs02 holds valid PFNs from the previous run of L2, then KVM could re-enter L2 with stale, unpinned PFNs mapped into e.g. the vAPIC page.
Note, both SVM and VMX (as of commit 11722439fb20 ("KVM: nVMX: Ensure KVM_REQ_GET_NESTED_STATE_PAGES is cleared on VM-Exit") ensure the request is cleared on VM-Exit (including the "forced" case), i.e. there is no risk of double-mapping due to emulated VMLAUNCH/VMRESUME/VMRUN and the request trying to map the nested pages.
This page as .md · .json · in your agent: get_signal("CVE-2026-98863")
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