CVE-2026-33841
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 Kernel allows an authorized attacker to elevate privileges 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 confidenceA heap-based buffer overflow vulnerability in the Windows Kernel enables a locally authenticated attacker to execute code with elevated privileges. The flaw exists in kernel-mode memory handling, allowing a local user to corrupt heap memory and achieve privilege escalation from a standard user account to SYSTEM or equivalent administrative rights.
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< 10.0.19044.7291< 10.0.19045.7291< 10.0.22631.7079< 10.0.26100.8390< 10.0.26200.8390< 10.0.28000.2113< 10.0.20348.5074< 10.0.25398.2330CVSS 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 installed Windows versionRun 'winver' from command prompt or 'systeminfo' from command prompt and note the OS version and build number displayedAffected if The version and build number fall below any of these thresholds: Windows 10 21h2 build 19044.7291, Windows 10 22h2 build 19045.7291, Windows 11 23h2 build 22631.7079, Windows 11 24h2 build 26100.8390, Windows 11 25h2 build 26200.8390, Windows 11 26h1 build 28000.2113, Windows Server 2022 build 20348
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Verify local user presenceRun 'net user' from an elevated command prompt to list local user accounts on the systemAffected if There are any local user accounts present on the system (excluding the built-in Administrator and Guest accounts) as the vulnerability requires a locally authenticated attacker to exploit it
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Check for untrusted local users with interactive logon rightsRun 'net localgroup Users' from command prompt to see which users belong to the Users group, or check Local Security Policy (secpol.msc) > Local Policies > User Rights Assignment for 'Allow log on locally'Affected if Any standard non-admin local users have interactive logon capability, as these accounts could potentially exploit the vulnerability to escalate privileges
A system is affected if it runs a Windows version with a build number lower than the thresholds listed AND has local user accounts that could trigger the heap overflow in kernel-mode memory handling.
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 · scoped10.0.19044.729110.0.19045.729110.0.20348.5074
Apply Microsoft security updates for Windows Kernel once available. Until a patch is released, restrict local user privileges, monitor for suspicious kernel-level process activity, and ensure endpoint detection and response solutions are configured to alert on potential privilege escalation attempts.
Upgrade to the specified fixed build versions (19044.7291, 19045.7291, 22631.7079, 26100.8390, 26200.8390, 28000.2113, 20348.5074, or 25398.2330 depending on Windows version/edition)
- 1. Identify the current Windows version by running 'winver' or 'systeminfo' in Command Prompt
- 2. Determine which build version is installed (e.g., 10.0.19044.xxxx)
- 3. For Windows 10 21h2 (build 19044): Upgrade to build 10.0.19044.7291 or later
- 4. For Windows 10 22h2 (build 19045): Upgrade to build 10.0.19045.7291 or later
- 5. For Windows 11 23h2 (build 22631): Upgrade to build 10.0.22631.7079 or later
- 6. For Windows 11 24h2 (build 26100): Upgrade to build 10.0.26100.8390 or later
- 7. For Windows 11 25h2 (build 26200): Upgrade to build 10.0.26200.8390 or later
- 8. For Windows 11 26h1 (build 28000): Upgrade to build 10.0.28000.2113 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-33841 — 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-2026-33841 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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- Version or environment caveats, and links to real fixes
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