dbcve.org
Windows 10 1507Operating system · Microsoft

CVE-2025-49659

HIGH · 7.8 CVSS v3.1 Published 2025-07-08
Fix available
A fix is available. Upgrade to 10.0.10240.21073 / 10.0.14393.8246 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

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 · unedited
Buffer over-read in Windows TDX.sys allows an authorized 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 confidence

A buffer over-read vulnerability exists in Windows TDX.sys, a kernel-mode driver related to Trusted Exchange Data Transport. An authorized local attacker can exploit this to elevate privileges, potentially gaining administrator or SYSTEM-level access on the affected Windows system.

MitigationApply Microsoft security updates for TDX.sys once released. Prioritize patching servers and workstations running Windows Server 2022, Windows 11, or Windows 10 systems with TDX components enabled.

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
Windows 10 1507Operating system
Affected:< 10.0.10240.21073
Windows 10 1607Operating system
Affected:< 10.0.14393.8246
Windows 10 1809Operating system
Affected:< 10.0.17763.7558
Windows 10 21h2Operating system
Affected:< 10.0.19044.6093
Windows 10 22h2Operating system
Affected:< 10.0.19045.6093
Windows 11 22h2Operating system
Affected:< 10.0.22621.5624
Windows 11 23h2Operating system
Affected:< 10.0.22631.5624
Windows 11 24h2Operating system
Affected:< 10.0.26100.4652

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check if TDX driver exists on the system
    Navigate to C:\Windows\System32\drivers\ and look for TDX.sys file. Alternatively, run 'driverquery /v | findstr TDX' in an elevated command prompt to list driver details.
    Affected if TDX.sys file is present on the system and the driver is loaded or available
  2. Verify Windows version is within affected range
    Run 'winver' or 'systeminfo' from command prompt to obtain the Windows build number. Compare against: Windows 10 1507 < 10.0.10240.21073, 1607 < 10.0.14393.8246, 1809 < 10.0.17763.7558, 21h2 < 10.0.19044.6093, 22h2 < 10.0.19045.6093, Windows 11 22h2 < 10.0.22621.5624, 23h2 < 10.0.22631.5624, 24h2 < 10.0.26100.4652.
    Affected if The installed Windows build number is lower than the fixed version for that specific release
  3. Confirm TDX feature is enabled
    Check registry key HKLM\SYSTEM\CurrentControlSet\Services\TDX for the Start value. Also check for presence of TDX-related components via 'sc query TDX' or review installed optional features for Trusted Exchange Data Transport support.
    Affected if The TDX driver service is present and set to start (Start value 0, 1, 2, or 3 indicates the driver could be loaded)
  4. Retrieve TDX.sys file version directly
    Right-click TDX.sys in C:\Windows\System32\drivers\, select Properties, then view the Details tab for File Version. Alternatively, run 'powershell (Get-Item C:\Windows\System32\drivers\TDX.sys).VersionInfo' to programmatically extract version info.
    Affected if The TDX.sys file version is lower than the version corresponding to the fixed Windows build for your release

The system is affected if TDX.sys is present and the Windows build number is below the fixed version for that specific Windows release.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 10.0.10240.21073 / 10.0.14393.8246 / 10.0.17763.7558 or later
Fixed in 10.0.10240.2107310.0.14393.824610.0.17763.7558
Interim mitigation

Apply Microsoft security updates for TDX.sys once released. Prioritize patching servers and workstations running Windows Server 2022, Windows 11, or Windows 10 systems with TDX components enabled.

Recommended fix High confidence

Windows 10 1507: 10.0.10240.21073 | Windows 10 1607: 10.0.14393.8246 | Windows 10 1809: 10.0.17763.7558 | Windows 10 21h2: 10.0.19044.6093 | Windows 10 22h2: 10.0.19045.6093 | Windows 11 22h2: 10.0.22621.5624 | Windows 11 23h2: 10.0.22631.5624 | Windows 11 24h2: 10.0.26100.4652

  1. Open Windows Settings on the affected system
  2. Navigate to Windows Update (Settings > Update & Security > Windows Update)
  3. Click 'Check for updates' to download and install the latest security updates
  4. Ensure the update includes the fix for CVE-2025-49659 (TDX.sys buffer over-read)
  5. Restart the system if prompted to complete the installation
  6. Verify the installed version matches or exceeds the fixed build number for your Windows version
Caveat Standard Windows security update; no breaking changes expected for typical workloads

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 10 1507 Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA4.0 h
40.0 hours of engineering $7,000
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-49659 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data