CVE-2026-54991
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 · uneditedConcurrent execution using shared resource with improper synchronization ('race condition') in Windows USB Print Driver 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 race condition vulnerability exists in the Windows USB Print Driver where concurrent execution of operations on shared resources lacks proper synchronization. An authorized local attacker can exploit this timing-sensitive flaw to elevate their privileges on the system.
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< 10.0.26100.8875< 10.0.26200.8875< 10.0.28000.2525< 10.0.26100.33158CVSS 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
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/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 versionRun 'winver' or 'systeminfo | findstr /B /C:"OS Version"' to obtain the full build numberAffected if Build number falls below 10.0.26100.8875 for Windows 11 24h2/Server 2025, below 10.0.26200.8875 for Windows 11 25h2, or below 10.0.28000.2525 for Windows 11 26h1
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Verify print spooler service statusRun 'sc query spooler' to check if the Print Spooler service is installed and runningAffected if Service is running (the USB Print Driver vulnerability requires the print subsystem to be active)
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List installed print driversRun 'pnputil /enum-drivers' or check 'C:\Windows\System32\spool\drivers' directory for USB-related print driversAffected if Any USB Print Driver is present in the installed print driver list
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Check USB printing support enabledReview registry key 'HKLM\SYSTEM\CurrentControlSet\Control\Print\Printers' or check 'Devices and Printers' in Control Panel for USB printer entriesAffected if USB printer devices are configured or USB printing is enabled in the system
A system is affected if it runs any of the listed Windows versions below the specified build thresholds AND has the USB Print Driver or print spooler functionality active.
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 data10.0.26100.887510.0.26100.3315810.0.26200.8875
Apply vendor-supplied patches for the Windows USB Print Driver when available; prioritize patching systems with untrusted local users. Consider restricting access to print driver functionality as a defense-in-depth measure.
- Consultation4.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,920.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-54991 — 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-2026-54991 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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