CVE-2026-50489
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 · uneditedHeap-based buffer overflow in Windows Win32K allows an authorized attacker to elevate privileges locally.
In the news
Third-party coverage- Microsoft July 2026 Patch Tuesday fixes massive 570 flaws, 3 zero-days
- Microsoft CVE Summary - Bleeping Computer
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 confidenceA heap-based buffer overflow vulnerability exists in Windows Win32K (the kernel-mode graphics subsystem) that allows a locally authorized attacker to elevate their privileges to higher permission levels.
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< 10.0.14393.9339< 10.0.17763.9020< 10.0.19044.7548< 10.0.19045.7548< 10.0.26100.8875< 10.0.26200.8875< 10.0.28000.2525all versions= r2CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check Windows build numberOpen Command Prompt and run `winver` or `systeminfo | findstr /B /C:"OS Version"` to obtain the full build numberAffected if The build number is lower than the affected version for your Windows release (e.g., below 10.0.14393.9339 for Windows 10 1607, below 10.0.17763.9020 for Windows 10 1809, etc.)
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Confirm Windows editionRun `winver` to identify whether you are on Windows 10 or Windows 11, and note the specific release (such as 1607, 1809, 21h2, 22h2, 24h2, 25h2, 26h1) or Windows Server 2012/R2Affected if The system runs any Windows 10 release 1607 through 22h2, Windows 11 24h2 through 26h1, or Windows Server 2012/R2, and the build number falls below the patched version for that release
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Verify Win32K.sys presenceConfirm the file exists at `C:\Windows\System32\win32k.sys` - this is the kernel-mode graphics subsystem driver that contains the vulnerabilityAffected if The win32k.sys file exists, which it does on all supported Windows desktop and server installations; the vulnerability resides in this component regardless of configuration
You are affected if your Windows version matches any of the listed releases AND your build number is below the specified threshold for that release (or any Windows Server 2012/R2 variant, which has no patched version listed).
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.
From vendor data10.0.14393.933910.0.17763.902010.0.19044.7548
Apply Microsoft security updates for Win32K.sys once available, as this is a kernel-level vulnerability requiring system-level patching rather than application configuration changes.
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-50489 — 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-2026-50489 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
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- 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
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