CVE-2026-33834
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 · uneditedImproper access control in Windows Event Logging Service 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 confidenceImproper access control in Windows Event Logging Service allows a local attacker with existing authorization to escalate privileges to higher permission levels. The vulnerability stems from insufficient validation of access permissions within the event logging subsystem, potentially allowing manipulation of event logs or abuse of the service's elevated context.
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< 10.0.14393.9140< 10.0.17763.8755< 10.0.19044.7291< 10.0.19045.7291< 10.0.22631.7079< 10.0.26100.8390< 10.0.26200.8390< 10.0.28000.2113CVSS 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 build numberRun 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to obtain the full Windows version and build number.Affected if The build number falls below any of these thresholds: 14393.9140 (Win10 1607), 17763.8755 (Win10 1809), 19044.7291 (Win10 21h2), 19045.7291 (Win10 22h2), 22631.7079 (Win11 23h2), 26100.8390 (Win11 24h2), 26200.8390 (Win11 25h2), 28000.2113 (Win11 26h1)
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Verify Windows edition matches affected listRun 'winver' to confirm the specific Windows edition (e.g., Windows 10 1607, Windows 11 23h2) and ensure it is one of the affected editions listed in the CVE.Affected if The edition is Windows 10 1607, 1809, 21h2, 22h2, or Windows 11 23h2, 24h2, 25h2, or 26h1 and the build number is below the corresponding threshold.
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Confirm Event Log service is runningOpen Services (services.msc) or run 'sc query eventlog' and 'sc query wevtsvc' to verify the Windows Event Log service is enabled and running.Affected if The event logging service is present and running, which is the default configuration on affected Windows versions.
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Review event log security permissionsOpen Event Viewer, right-click each log (Security, Application, System), select Properties, and inspect the Security tab to verify which users or groups have write or full control permissions.Affected if Non-administrator users or groups outside of expected privileged accounts have Write or Full Control permissions to Security, System, or Application event logs.
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Audit recent event log modificationsRun 'wevtutil qe Security /c:50 /f:text' or open Security event log and look for Event ID 1102 (log cleared) or 1100 (service stopped) as indicators of potential abuse.Affected if Unusual or unauthorized event log clearing, modification, or service restarts are observed, especially from low-privilege accounts.
You are affected if your Windows version matches one of the listed editions AND your current build number is below the specified threshold for that edition, combined with any unexpected permissions on event logs.
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 · scoped10.0.14393.914010.0.17763.875510.0.19044.7291
Apply the relevant Microsoft security update for this vulnerability once available. Until then, restrict local access to trusted users only and monitor for suspicious event log manipulation.
Upgrade to the specific build number for your Windows release as listed above, or install the latest cumulative update from Microsoft Update Catalog for your Windows version
- 1. Identify the current Windows version by running 'winver' or 'systeminfo' in Command Prompt
- 2. Determine which Windows 10 or 11 release version is installed and note the build number
- 3. For Windows 10 1607 systems: upgrade to build 10.0.14393.9140 or later
- 4. For Windows 10 1809 systems: upgrade to build 10.0.17763.8755 or later
- 5. For Windows 10 21h2 systems: upgrade to build 10.0.19044.7291 or later
- 6. For Windows 10 22h2 systems: upgrade to build 10.0.19045.7291 or later
- 7. For Windows 11 23h2 systems: upgrade to build 10.0.22631.7079 or later
- 8. For Windows 11 24h2 systems: upgrade to build 10.0.26100.8390 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-33834 — 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-2026-33834 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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