CVE-2026-20852
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 · uneditedIncorrect privilege assignment in Windows Hello allows an unauthorized attacker to perform tampering locally.
In the news
Third-party coverage- Microsoft CVE Summary - Bleeping Computer
- Microsoft January 2026 Patch Tuesday fixes 3 zero-days, 114 flaws
Surfaced from public web coverage — external links open in a new tab.
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 confidenceThis vulnerability involves incorrect privilege assignment within Windows Hello, Microsoft's biometric and PIN authentication system. A local attacker with unauthorized access can exploit this privilege misconfiguration to perform tampering operations, potentially modifying authentication settings, credentials, or the Hello configuration itself. The local attack vector suggests physical access or an already-compromised local user account is required.
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< 10.0.14393.8783< 10.0.17763.8276< 10.0.19044.6809< 10.0.19045.6809< 10.0.22631.6491< 10.0.26100.7623< 10.0.26200.7623< 10.0.14393.8783CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 checksWork through these to decide whether this CVE applies to you.
-
Check Windows version against affected rangesRun 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to obtain the exact Windows build numberAffected if The build number falls below any of these thresholds: 14393.8783 (Win 10 1607/Server 2016), 17763.8276 (Win 10 1809), 19044.6809 (Win 10 21h2), 19045.6809 (Win 10 22h2), 22631.6491 (Win 11 23h2), 26100.7623 (Win 11 24h2), or 26200.7623 (Win 11 25h2)
-
Verify Windows Hello is configuredGo to Settings > Accounts > Sign-in options or run 'manage-bde -status' (for BitLocker) or check Registry: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\HelloAffected if Windows Hello for Business or Windows Hello (biometric/PIN) is enabled on the system
-
Check user privilege assignments related to credential managementRun 'whoami /priv' to list current user privileges, then review if any unauthorized users have been granted elevated privileges to modify authentication settingsAffected if Unexpected users or groups have privileges that allow modification of Windows Hello or credential settings
-
Audit Windows Hello configuration for unauthorized changesReview Windows Event Viewer under Security and Windows Hello for Business logs for event IDs related to credential enrollment or configuration changes performed by non-admin usersAffected if There are log entries showing Hello configuration changes made by users without appropriate authorization
A system is likely affected if it runs a Windows version below the patched build numbers AND has Windows Hello enabled, with evidence of improper privilege assignments that could allow unauthorized Hello configuration tampering.
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 · scoped10.0.14393.878310.0.17763.827610.0.19044.6809
Apply available Microsoft security updates for Windows Hello when released. Until a patch is available, limit physical access to affected systems and monitor for unauthorized changes to Windows Hello configuration or credential enrollment.
Upgrade to the fixed version specific to your Windows release (e.g., Windows 10 22h2 to 10.0.19045.6809 or later, Windows 11 23h2 to 10.0.22631.6491 or later)
- Identify the current Windows version by running 'winver' or checking System Information
- Determine if the current version is below the fixed threshold for your Windows release
- For Windows 10 1607/Server 2016: Upgrade to version 10.0.14393.8783 or later
- For Windows 10 1809: Upgrade to version 10.0.17763.8276 or later
- For Windows 10 21h2: Upgrade to version 10.0.19044.6809 or later
- For Windows 10 22h2: Upgrade to version 10.0.19045.6809 or later
- For Windows 11 23h2: Upgrade to version 10.0.22631.6491 or later
- For Windows 11 24h2: Upgrade to version 10.0.26100.7623 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,888.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20852 — 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-2026-20852 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
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.
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.
- 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