CVE-2026-12166
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 · uneditedA NULL pointer dereference vulnerability for driver `GFAC_Sys_x64.sys` in Little Orbit GFAC allows a local attacker to cause a denial of service via crafted requests that trigger a system crash.
In the news
Third-party coverageSurfaced 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 NULL pointer dereference vulnerability in the GFAC_Sys_x64.sys driver for Little Orbit GFAC allows a local attacker to cause a system crash by sending crafted requests that trigger the dereference of a NULL pointer in the driver's request handling code.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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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Locate the GFAC_Sys_x64.sys driver fileSearch for the file GFAC_Sys_x64.sys in the Windows\System32\drivers directory or the Little Orbit GFAC installation folderAffected if The driver file exists on the system, indicating the software is installed
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Check if the driver is currently loadedRun 'sc query GFAC' or check the driver list via 'driverquery /v' to see if the driver is activeAffected if The driver shows as RUNNING or LOADED in the output, meaning it is actively handling requests
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Identify the installed Little Orbit GFAC versionCheck the installed programs list in Control Panel or run 'Get-ItemProperty' on the GFAC installation directory for version metadataAffected if The installed version matches any vulnerable version range for this driver (compare against known affected versions)
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Review system crash logs for driver-related faultsOpen Event Viewer and search Application/System logs for BugCheck events or error entries referencing GFAC_Sys_x64.sys around the time of crashesAffected if Recent crash events list this driver as the faulting module, suggesting active exploitation or trigger conditions
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Verify driver request handling exposureConfirm the driver is bound to a device interface or accessible via local IPC that unprivileged users can send requests toAffected if The driver exposes an interface accessible to local users without admin rights, allowing crafted request injection
You are affected if the GFAC_Sys_x64.sys driver is loaded and the installed Little Orbit GFAC version falls within the vulnerable range, exposing the system to NULL pointer dereference crashes via crafted local requests.
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 dataApply the vendor-provided patch for this driver when available; until then, restrict local access to the system and monitor for anomalous driver requests that could indicate exploitation attempts.
- Consultation3.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-12166 — 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-2026-12166 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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