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Windows 10 21h2Operating system · Microsoft

CVE-2026-27931

MEDIUM · 5.5 CVSS v3.1 Published 2026-04-14
Fix available
A fix is available. Upgrade to 10.0.19044.7184 / 10.0.19045.7184 or later.
See remediation →
58/100
Remediation priority · Elevated
No privileges

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
Out-of-bounds read in Windows GDI allows an unauthorized 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

An out-of-bounds read vulnerability exists in Windows GDI (Graphics Device Interface) that allows a local, unauthorized attacker to read sensitive information from memory beyond allocated buffer boundaries.

MitigationApply the relevant Microsoft Windows security update to patch the GDI vulnerability. Prioritize endpoints based on exposure and criticality.

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 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 2022Operating system
Affected:< 10.0.20348.5020
Windows Server 2022 23h2Operating system
Affected:< 10.0.25398.2274

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
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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. Check Windows version and build number
    Open Command Prompt or PowerShell and run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to retrieve the exact Windows build number.
    Affected if The build number falls below any of the following thresholds: 19044.7184 (Win10 21h2), 19045.7184 (Win10 22h2), 22631.6936 (Win11 23h2), 26100.8246 (Win11 24h2), 26200.8246 (Win11 25h2), 28000.1836 (Win11 26h1), 20348.5020 (Server 2022), 25398.2274 (Server 2022 23h2)
  2. Confirm GDI component availability
    Verify that GDI-related DLLs such as gdi32.dll exist and are accessible on the system. Run 'dir %SystemRoot%\System32\gdi32.dll' to confirm the file is present.
    Affected if The gdi32.dll file exists on the system (this is the default state for all supported Windows installations, meaning the vulnerability surface is present if the version is unpatched)

A system is affected if it runs any of the listed Windows versions/builds and the installed build number is lower than the fixed version for that release branch.

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 10.0.19044.7184 / 10.0.19045.7184 / 10.0.20348.5020 or later
Fixed in 10.0.19044.718410.0.19045.718410.0.20348.5020
Interim mitigation

Apply the relevant Microsoft Windows security update to patch the GDI vulnerability. Prioritize endpoints based on exposure and criticality.

Recommended fix High confidence

Update to the latest Windows security update containing the CVE-2026-27931 patch, targeting the fixed build numbers (e.g., 10.0.19044.7184 or higher for Win10 21h2, 10.0.19045.7184 or higher for Win10 22h2, etc.)

  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 patch for CVE-2026-27931 (GDI out-of-bounds read)
  5. Restart the system after the update is installed
  6. Verify the installed Windows version meets or exceeds the fixed build number for your edition (10.0.19044.7184 for Win10 21h2, 10.0.19045.7184 for Win10 22h2, 10.0.22631.6936 for Win11 23h2, 10.0.26100.8246 for Win11 24h2, 10.0.26200.8246 for Win11 25h2, 10.0.28000.1836 for Win11 26h1, 10.0.20348.5020 for Server 2022, 10.0.25398.2274 for Server 2022 23h2)
Caveat Standard Windows update risks apply - ensure backups of critical data before applying; some updates may require restarts

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

Fix this in Windows 10 21h2 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $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-2026-27931 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