CVE-2026-98863
Received
Received - Intake
KVM: x86 Nested State Page Handling Failure
Vulnerability report for CVE-2026-98863, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-18
Last updated on: 2026-10-18
Assigner: kernel.org
Description
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 671ddc700fd08b94967b1e2a937020e30c838609 |
| Linux | Linux | 671ddc700fd08b94967b1e2a937020e30c838609 |
| Linux | Linux | 671ddc700fd08b94967b1e2a937020e30c838609 |
| Linux | Linux | 5.4 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
