CVE-2026-12167
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 · uneditedThe Minifilter communication port for driver `GFAC_Sys_x64.sys` in Little Orbit GFAC allows a local attacker to access privileged driver functionality via a communication interface that lacks appropriate access restrictions.
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 minifilter driver (GFAC_Sys_x64.sys) used by Little Orbit GFAC exposes a communication port without proper access restrictions, allowing a local attacker to send privileged commands to the kernel-mode driver. This constitutes a local privilege escalation vulnerability where unprivileged users can invoke driver functionality intended for higher-privileged processes.
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
- 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 for GFAC driver file presenceSearch for GFAC_Sys_x64.sys in system driver directories: Get-ChildItem -Path C:\Windows\System32\drivers -Filter *GFAC* -Recurse -ErrorAction SilentlyContinueAffected if The driver file GFAC_Sys_x64.sys exists in the system drivers directory
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Verify if the minifilter driver is loadedQuery the filter manager for active minifilters: fltmc.exe filters 2>$null | Select-String -Pattern 'GFAC' or check via Sysinternals Autoruns for GFAC driver entriesAffected if The GFAC minifilter driver is loaded and running on the system
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Identify the communication port exposed by the minifilterUse Process Monitor (ProcMon) to monitor for communication port creation events matching '\\MiniFilter\\' patterns, or enumerate minifilter ports using NtObjectManager: Get-NtMiniFilter -CommunicationPortsAffected if A minifilter communication port associated with GFAC is created and accessible
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Verify port access permissions allow unprivileged accessAttempt to open the communication port from a low-privilege context, or use WinObj to examine the security descriptor on the minifilter communication port object - check that only privileged users/processes have accessAffected if The communication port grants access to unprivileged users or has no restrictive security descriptor, allowing any local user to send commands to the driver
If GFAC_Sys_x64.sys is present and its minifilter communication port is exposed without proper access restrictions, the system is vulnerable to local privilege escalation via unprivileged user access to kernel-mode driver functionality.
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 dataImplement proper security descriptors when creating the minifilter communication port using FltCreateCommunicationPort with a valid SECURITY_DESCRIPTOR that restricts access to authorized users/processes only.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 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 $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-12167 — 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-2026-12167 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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