CVE-2026-42488
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedSome shadow paging errors paths will switch the page-tables without updating the currently running vCPU reference. This causes a mismatch between the loaded page-tables and the mapcache metadata which can lead to corruption of the mapcache.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThis is a hypervisor vulnerability in shadow paging implementation where error handling paths switch page-tables without updating the running vCPU reference, causing a mismatch between loaded page-tables and mapcache metadata that leads to mapcache corruption.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify your hypervisor and versionRun 'hypervisor -v' or check system information to determine which hypervisor software is running and its installed version numberAffected if The hypervisor implements shadow paging and the installed version falls within the affected range (if known)
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Verify if shadow paging is enabledCheck hypervisor configuration files or runtime settings for shadow paging or related page-table virtualization features (e.g., look for 'shadow_paging', 'nested_paging', or similar configuration flags)Affected if Shadow paging is actively enabled in the hypervisor configuration
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Check for mapcache-related errorsReview hypervisor logs and system event logs for errors containing 'mapcache', 'page-table mismatch', or 'shadow page' keywords, especially around error handling or migration eventsAffected if Mapcache corruption errors or page-table mismatch warnings appear in logs
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Confirm workload typeIdentify if the hypervisor runs untrusted or third-party virtual machines, particularly those that may trigger error handling paths in shadow paging codeAffected if Untrusted workloads are executed on the hypervisor with shadow paging enabled
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Inspect vCPU state during errorsIf possible, examine vCPU state during or after error conditions for references to incorrect page-table pointers or mismatched mapping metadataAffected if vCPU shows loaded page-tables that do not match the mapcache metadata
Your environment is affected if you run a hypervisor with shadow paging enabled and observe mapcache corruption or page-table mismatch errors, particularly during error handling scenarios.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply vendor-supplied patches to the hypervisor; until then, minimize exposure by avoiding untrusted workloads on affected virtualization platforms.
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-42488 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-42488 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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