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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 3 May 2022.
Windows 10 1507Operating system · Microsoft

CVE-2020-17087

HIGH · 7.8 CVSS v3.1 Developing Published 2020-11-11
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
96/100
Remediation priority · Urgent
In the wild Zero-click Patch available

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
Windows Kernel Local Elevation of Privilege Vulnerability

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 · low confidence

A local privilege escalation vulnerability in the Windows kernel allows an authenticated attacker to elevate privileges to SYSTEM level by exploiting a flaw in how the kernel handles certain objects. This is a local attack vector requiring valid credentials but can lead to complete system compromise.

MitigationApply the Microsoft security update for CVE-2020-17087, which was released as part of the November 2020 Patch Tuesday. Prioritize patching domain controllers and systems with sensitive data or exposed attack surfaces.

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:all versions
Windows 10 1607Operating system
Affected:all versions
Windows 10 1803Operating system
Affected:all versions
Windows 10 1809Operating system
Affected:all versions
Windows 10 1903Operating system
Affected:all versions
Windows 10 1909Operating system
Affected:all versions
Windows 10 2004Operating system
Affected:all versions
Windows 10 20h2Operating system
Affected:all versions

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 Windows 10 version and build number
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to identify the exact Windows 10 version and build number
    Affected if The build number is below the patched build for your Windows 10 release (for example, builds below 18362.1257 for 1903/1909, below 19041.631 for 2004)
  2. Identify the specific Windows 10 release
    Run 'reg query "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion" /v ReleaseId' to get the release ID (e.g., 1909, 2004)
    Affected if The release ID matches any of the affected versions: 1507, 1607, 1803, 1809, 1903, 1909, 2004, or 20h2
  3. Verify November 2020 security update is installed
    Open Control Panel > Programs and Features > View installed updates, or run 'wmic qfe list' to list installed hotfixes, looking for KB4586781 (2004), KB4586793 (1903/1909), or corresponding KB for your release
    Affected if No November 2020 security update (KB4586xxx series) is installed for your specific Windows 10 version
  4. Check kernel patch status via registry
    Run 'reg query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Component Based Servicing\Packages" /s | findstr "Package_for"' to list installed servicing stack updates
    Affected if The November 2020 servicing stack update for your Windows 10 release is missing
  5. Confirm system is unpatched by checking build against known vulnerable versions
    Compare your build number to the affected ranges: 1507 (builds before 10240), 1607 (builds before 14393), 1803 (builds before 17134), 1809 (builds before 17763), 1903/1909 (builds before 18362), 2004 (builds before 19041), 20h2 (builds before 19042)
    Affected if Your current build number falls within the pre-patched range for your Windows 10 release

You are affected if you are running any Windows 10 version 1507 through 20h2 and the November 2020 security updates are not installed, or if your build number is below the patched threshold for your specific 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
Patch available Apply the vendor patch
Vendor patch portal.msrc.microsoft.com →
Interim mitigation

Apply the Microsoft security update for CVE-2020-17087, which was released as part of the November 2020 Patch Tuesday. Prioritize patching domain controllers and systems with sensitive data or exposed attack surfaces.

Recommended fix Moderate confidence

Windows 10 21H1 or later; or apply November 2020 security updates for your current Windows 10 version

  1. Apply Microsoft security updates released November 2020 for CVE-2020-17087 via Windows Update or Microsoft Update Catalog
  2. Verify the patch is installed by checking Windows Update history for KB4586786 (Windows 10 1909) or KB4586781 (Windows 10 2004) depending on your version
  3. Alternatively, upgrade to a later Windows 10 version (21H1 or later) which includes the security fix
Caveat None expected for security patch; minor upgrade path risks apply when moving between major Windows 10 feature releases

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

Fix this in Windows 10 1507 Exploited in the wild — priority engagement
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

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dbcve dependency scanner

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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-2020-17087 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