Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 4 Nov 2025.
Windows 10 1507Operating system · Microsoft

CVE-2025-24990

HIGH · 7.8 CVSS v3.1 Published 2025-10-14
Fix available
A fix is available. Upgrade to 10.0.10240.21161 / 10.0.14393.8519 or later.
See remediation →
96/100
Remediation priority · Urgent
In the wild 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
Microsoft is aware of vulnerabilities in the third party Agere Modem driver that ships natively with supported Windows operating systems. This is an announcement of the upcoming removal of ltmdm64.sys driver. The driver has been removed in the October cumulative update. Fax modem hardware dependent on this specific driver will no longer work on Windows. Microsoft recommends removing any existing dependencies on this hardware.

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 · high confidence

A vulnerable Agere modem driver (ltmdm64.sys) that shipped natively with supported Windows operating systems has been removed in the October cumulative update. The driver contained security vulnerabilities (CVSS 7.8) that could be exploited, prompting Microsoft to remove it entirely rather than patch it. Any fax modem hardware dependent on this specific driver will no longer function.

MitigationOrganizations should inventory systems for Agere modem hardware dependencies and remove the driver or replace the hardware before the update deploys. Microsoft recommends eliminating dependencies on this hardware entirely as no replacement driver is being provided.

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:< 10.0.10240.21161
Windows 10 1607Operating system
Affected:< 10.0.14393.8519
Windows 10 1809Operating system
Affected:< 10.0.17763.7919
Windows 10 21h2Operating system
Affected:< 10.0.19044.6456
Windows 10 22h2Operating system
Affected:< 10.0.19045.6456
Windows 11 22h2Operating system
Affected:< 10.0.22621.6060
Windows 11 23h2Operating system
Affected:<= 10.0.22631.6060
Windows 11 24h2Operating system
Affected:< 10.0.26100.6899

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 ltmdm64.sys driver file exists
    Search for the file ltmdm64.sys in system directories. Typical paths include C:\Windows\System32\drivers\ and C:\Windows\System32\DriverStore\. Use: Get-ChildItem -Path C:\Windows -Recurse -Filter ltmdm64.sys -ErrorAction SilentlyContinue
    Affected if The driver file is present on the system
  2. Verify Windows build number
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Version"' to obtain the Windows build number
    Affected if The build number falls within the affected ranges: < 10.0.10240.21161 (1507), < 10.0.14393.8519 (1607), < 10.0.17763.7919 (1809), < 10.0.19044.6456 (21h2), < 10.0.19045.6456 (22h2), < 10.0.22621.6060 (Win11 22h2), <= 10.0.22631.6060 (Win11 23h2), < 10.0.26100.6899 (Win11 24h2)
  3. Confirm driver is loaded or present in driver store
    Run 'driverquery /v | findstr ltmdm64' or check registry under HKLM\SYSTEM\CurrentControlSet\Services\ltmdm64 for the presence of this driver
    Affected if The driver is listed as installed or loaded in the system driver database

The system is affected if the ltmdm64.sys driver file exists and the Windows build number is within any of the affected version ranges listed.

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 10.0.10240.21161 / 10.0.14393.8519 / 10.0.17763.7919 or later
Fixed in 10.0.10240.2116110.0.14393.851910.0.17763.7919
Interim mitigation

Organizations should inventory systems for Agere modem hardware dependencies and remove the driver or replace the hardware before the update deploys. Microsoft recommends eliminating dependencies on this hardware entirely as no replacement driver is being provided.

Recommended fix High confidence

October cumulative update for respective Windows version (Windows 10 1507: 10.0.10240.21161, Windows 10 1607: 10.0.14393.8519, Windows 10 1809: 10.0.17763.7919, Windows 10 21h2: 10.0.19044.6456, Windows 10 22h2: 10.0.19045.6456, Windows 11 22h2: 10.0.22621.6060, Windows 11 23h2: 10.0.22631.6060, Win

  1. Install the October cumulative update (or later) for your Windows version via Windows Update or Microsoft Update Catalog
  2. Restart the system after applying the update
  3. Verify the ltmdm64.sys driver has been removed by checking Device Manager or running 'driverquery /v | findstr ltmdm64'
  4. If fax modem hardware dependent on this driver no longer functions, this is expected behavior - Microsoft recommends removing dependencies on this hardware
Caveat Fax modem hardware dependent on the ltmdm64.sys driver will no longer function - the driver has been completely removed, not patched

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

Fix this in Windows 10 1507 Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2025-24990 in production — separate from our analysis above.

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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