dbcve.org
Windows 10 1809Operating system · Microsoft

CVE-2026-20806

MEDIUM · 5.5 CVSS v3.1 Published 2026-04-14
Fix available
A fix is available. Upgrade to 10.0.17763.8644 / 10.0.19044.7184 or later.
See remediation →
57/100
Remediation priority · Elevated
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
Access of resource using incompatible type ('type confusion') in Windows COM allows an authorized attacker to disclose information 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

Type confusion vulnerability in Windows Component Object Model (COM) allows an authorized local attacker to access sensitive information due to improper type handling when accessing resources.

MitigationApply the Microsoft security update for CVE-2026-20806 when released through Windows Update or patch management systems.

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 1809Operating system
Affected:< 10.0.17763.8644
Windows 10 21h2Operating system
Affected:< 10.0.19044.7184
Windows 10 22h2Operating system
Affected:< 10.0.19045.7184
Windows 11 23h2Operating system
Affected:< 10.0.22631.6936
Windows 11 24h2Operating system
Affected:< 10.0.26100.8246
Windows 11 25h2Operating system
Affected:< 10.0.26200.8246
Windows 11 26h1Operating system
Affected:< 10.0.28000.1836
Windows Server 2019Operating system
Affected:< 10.0.17763.8644

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
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

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. Identify Windows version and build number
    Run `systeminfo` in Command Prompt or use PowerShell `Get-ComputerInfo | Select-Object OsName, OsVersion, OsBuildNumber`
    Affected if The build number falls below the threshold for your Windows release as listed in the affected versions
  2. Confirm exact build number from system registry
    Query the registry key `HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion` and note the `CurrentBuild` and `DisplayVersion` values
    Affected if The build number displayed is lower than the specified threshold for your Windows version (e.g., Windows 10 22h2 below 10.0.19045.7184)
  3. Map build number to affected version range
    Cross-reference your identified build number against the listed affected products and versions
    Affected if Your Windows version and build match any of the vulnerable ranges: Windows 10 1809 < 10.0.17763.8644, Windows 10 21h2 < 10.0.19044.7184, Windows 10 22h2 < 10.0.19045.7184, Windows 11 23h2 < 10.0.22631.6936, Windows 11 24h2 < 10.0.26100.8246, Windows 11 25h2 < 10.0.26200.8246, Windows 11 26h1 < 10.0.

You are affected if your Windows version matches one of the listed products AND your build number is lower than the corresponding threshold, meaning the system is unpatched for CVE-2026-20806.

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 10.0.17763.8644 / 10.0.19044.7184 / 10.0.19045.7184 or later
Fixed in 10.0.17763.864410.0.19044.718410.0.19045.7184
Interim mitigation

Apply the Microsoft security update for CVE-2026-20806 when released through Windows Update or patch management systems.

Recommended fix High confidence

Install the Microsoft security update for CVE-2026-20806 to reach the fixed build for your Windows version

  1. Identify the current Windows version and build number (winver or systeminfo)
  2. For Windows 10 1809: Upgrade to build 10.0.17763.8644 or later
  3. For Windows 10 21h2: Upgrade to build 10.0.19044.7184 or later
  4. For Windows 10 22h2: Upgrade to build 10.0.19045.7184 or later
  5. For Windows 11 23h2: Upgrade to build 10.0.22631.6936 or later
  6. For Windows 11 24h2: Upgrade to build 10.0.26100.8246 or later
  7. For Windows 11 25h2: Upgrade to build 10.0.26200.8246 or later
  8. For Windows 11 26h1: Upgrade to build 10.0.28000.1836 or later
Caveat Standard Windows update process; review update compatibility for mission-critical systems before deployment

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

Fix this in Windows 10 1809 Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-20806 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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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-2026-20806 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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