dbcve.org
365 CopilotApplication · Microsoft

CVE-2026-50387

HIGH · 7.8 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 10.0.14393.9339 / 10.0.17763.9020 or later.
See remediation →
80/100
Remediation priority · High
Zero-click 5 weeks old

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
Stack-based buffer overflow in Windows GDI allows an authorized attacker to elevate privileges locally.

In the news

Third-party coverage
Trending covered by 1 outlet this week · latest 1mo ago

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 confidence

A stack-based buffer overflow exists in Windows GDI (Graphics Device Interface) that allows a locally authorized attacker to elevate privileges to higher integrity levels. The vulnerability stems from improper bounds checking in GDI component handling, enabling an attacker with local access to overwrite stack memory and execute arbitrary code with elevated privileges.

MitigationApply Microsoft security patches for Windows GDI when released. Until then, limit local user privileges, enforce least-privilege policies, and monitor for suspicious processes attempting to exploit graphics subsystem components.

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
365 CopilotApplication
Affected:all versions
Microsoft 365Application
Affected:all versions
Office 2021Application
Affected:all versions
Office 2024Application
Affected:all versions
Windows 10 1607Operating system
Affected:< 10.0.14393.9339
Windows 10 1809Operating system
Affected:< 10.0.17763.9020
Windows 10 21h2Operating system
Affected:< 10.0.19044.7548
Windows 10 22h2Operating system
Affected:< 10.0.19045.7548

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 build version
    Open Command Prompt and run 'winver' or 'systeminfo | findstr /B /C:"OS Version"' to see the installed build number
    Affected if The build number falls below any of these thresholds: 14393.9339 (1607), 17763.9020 (1809), 19044.7548 (21h2), or 19045.7548 (22h2)
  2. Verify Windows 10 release version
    Run 'winver' to confirm which Windows 10 release (1607, 1809, 21h2, or 22h2) is installed, then cross-reference with the build number from step 1
    Affected if The detected release version has a build number lower than the corresponding threshold for that release
  3. Determine if affected Office or Microsoft 365 products are installed
    Open Programs and Features or run 'Get-ItemProperty HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\* | Select-Object DisplayName, DisplayVersion' in PowerShell to list installed Microsoft Office products
    Affected if Any version of Microsoft Office 2021, Microsoft Office 2024, Microsoft 365, or Microsoft 365 Copilot is installed on the system
  4. Confirm GDI component availability
    GDI (gdi32.dll) is a core Windows component present on all Windows systems. Verify its presence by checking %SystemRoot%\System32\gdi32.dll
    Affected if The system is running an affected Windows version as determined in steps 1-2 - GDI is inherently in use by the graphics subsystem
  5. Audit local user privileges
    Run 'net user' or check Local Users and Groups (lusrmgr.msc) to enumerate local user accounts
    Affected if The environment has multiple local users where an attacker with lower privileges could attempt to exploit this vulnerability for privilege escalation

You are affected if running any Windows 10 version within the specified build ranges AND the system has local user accounts that could be exploited for privilege escalation.

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.

From vendor data
Upgrade available Upgrade to 10.0.14393.9339 / 10.0.17763.9020 / 10.0.19044.7548 or later
Fixed in 10.0.14393.933910.0.17763.902010.0.19044.7548
Interim mitigation

Apply Microsoft security patches for Windows GDI when released. Until then, limit local user privileges, enforce least-privilege policies, and monitor for suspicious processes attempting to exploit graphics subsystem components.

Fix this in 365 Copilot Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,160.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-50387 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2026-50387 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