CVE-2025-49689
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 · uneditedInteger overflow or wraparound in Virtual Hard Disk (VHDX) allows an unauthorized attacker to elevate privileges locally.
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 confidenceA vulnerability in the Virtual Hard Disk (VHDX) parsing functionality contains an integer overflow or wraparound condition that can be triggered by a specially crafted VHDX file, allowing a local unauthenticated attacker to execute code with elevated privileges.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 10.0.10240.21073< 10.0.14393.8246< 10.0.17763.7558< 10.0.19044.6093< 10.0.19045.6093< 10.0.22621.5624< 10.0.22631.5624< 10.0.26100.4652CVSS 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
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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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Check Windows version against affected rangesRun 'winver' or 'systeminfo' and compare the displayed Windows build number to the vulnerable version thresholds: Windows 10 1507 requires 10.0.10240.21073 or higher, Windows 10 1607 requires 10.0.14393.8246 or higher, Windows 10 1809 requires 10.0.17763.7558 or higher, Windows 10 21h2 requires 10.0.19044.6093 or higher, Windows 10 22h2 requires 10.0.19045.6093 or higher, Windows 11 22h2 requires 10.0.22621.5624 or higher, Windows 11 23h2 requires 10.0.22631.5624 or higher, Windows 11 24h2 requires 10.0.26100.4652 or higherAffected if The installed Windows build number is lower than the required patch version for your specific Windows release
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Identify if Hyper-V role is installedRun 'Get-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V' in PowerShell or check 'Programs and Features' for Hyper-V componentsAffected if Hyper-V is enabled and the Windows version is unpatched, as Hyper-V processes VHDX files for virtual machines
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Check for VHDX mounting capabilityRun 'Get-VHD *' in PowerShell to list any attached VHDX images, or check Disk Management (diskmgmt.msc) for any mounted virtual disks with .vhdx extensionAffected if Any VHDX files are mounted or attached on the system
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Review Event Logs for VHDX-related errorsOpen Event Viewer and check under 'Application and Services Logs > Microsoft > Windows > Hyper-V-VMMS' for any VHDX parsing errors or crash events around VHDX file operationsAffected if VHDX-related crash or parse error events appear in the logs indicating potential exploitation attempts
The system is affected if it runs an unpatched Windows version within the affected ranges AND has Hyper-V or VHDX mounting features enabled that could process a malicious VHDX file.
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.
dbcve · scoped10.0.10240.2107310.0.14393.824610.0.17763.7558
Apply vendor-provided security patches for affected virtualization and Windows products that handle VHDX files; restrict access to VHDX file creation and mounting to trusted users only until patches are applied.
Upgrade to Windows 10 1507 build 10.0.10240.21073, Windows 10 1607 build 10.0.14393.8246, Windows 10 1809 build 10.0.17763.7558, Windows 10 21h2 build 10.0.19044.6093, Windows 10 22h2 build 10.0.19045.6093, Windows 11 22h2 build 10.0.22621.5624, Windows 11 23h2 build 10.0.22631.5624, or Windows 11 2
- Identify the current Windows version by running 'winver' or 'systeminfo' in the command prompt
- Navigate to Windows Update (Settings > Update & Security > Windows Update) and check for available updates
- Install all cumulative security updates for the identified Windows version that include the fix for CVE-2025-49689
- Alternatively, download the specific security update from the Microsoft Update Catalog by searching for the KB article associated with this CVE (refer to msrc.microsoft.com for the specific KB number)
- Restart the computer after the update installation completes
- Verify the update was successful by checking the installed updates list or running 'winver' to confirm the version matches or exceeds the fixed build numbers
Generated from the published advisory — verify against the referenced sources before acting.
- 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-2025-49689 — 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-2025-49689 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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- 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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