CVE-2026-98863Hinoki check available

Stale-memory access via lost nested-page retry

Published Oct 18, 2026 · Updated Oct 18, 2026

Stale mappings in Linux x86 KVM allow local users to access unpinned memory through nested virtualization after a page-mapping failure. In vcpu_enter_guest(), consuming KVM_REQ_GET_NESTED_STATE_PAGES without restoring it on failure lets a subsequent KVM_RUN reuse old vmcs02 page addresses. Exposure requires nested virtualization and a userspace vCPU restart after failure; host memory reuse and host compromise were not demonstrated in the original report.

CVSS severityUnavailable
Unscored
EPSS probability0.15%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stale mappings in Linux x86 KVM allow local users to access unpinned memory through nested virtualization after a page-mapping failure. In vcpu_enter_guest(), consuming KVM_REQ_GET_NESTED_STATE_PAGES without restoring it on failure lets a subsequent KVM_RUN reuse old vmcs02 page addresses. Exposure requires nested virtualization and a userspace vCPU restart after failure; host memory reuse and host compromise were not demonstrated in the original report.

The record

CVE
CVE-2026-98863
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.4
  2. Affected versionversion=671ddc700fd08b94967b1e2a937020e30c838609 <10180a277549339020b08000206092c07e0bff5a
  3. Affected versionversion=671ddc700fd08b94967b1e2a937020e30c838609 <525694a6021ec6c8f7ce1f38acdf2dd77698fec1
  4. Affected versionversion=671ddc700fd08b94967b1e2a937020e30c838609 <942192dbcd3a06695ef6b31cf10a41a21cf014d8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=5.4; version=671ddc700fd08b94967b1e2a937020e30c838609 <10180a277549339020b08000206092c07e0bff5a; version=671ddc700fd08b94967b1e2a937020e30c838609 <525694a6021ec6c8f7ce1f38acdf2dd77698fec1; version=671ddc700fd08b94967b1e2a937020e30c838609 <942192dbcd3a06695ef6b31cf10a41a21cf014d8

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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