TcRouter.sys for Windows on x64 3.1.0.2364: Exposed IOCTL with Insufficient Access Control
CVE-2026-18767 is a high-severity exposed IOCTL with insufficient access control vulnerability in TcRouter.sys for Windows on x64 3.1.0.2364 from Beckhoff Automation, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected TcRouter.sys for Windows on x64 3.1.0.2364 versions: 3.1.0.2364. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.14% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update TcRouter.sys for Windows on x64 <3.1.0.2365 to 3.1.0.2365 or a later version.
- Update TcRouter.sys for Windows on x86 <3.1.0.2365 to 3.1.0.2365 or a later version.
- Update TwinCAT.XAR.Base.KM <3.18.1 to 3.18.1 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Beckhoff Automation | TcRouter.sys for Windows on x64 3.1.0.2364 | 3.1.0.2364 | Not stated |
| Beckhoff Automation | TcRouter.sys for Windows on x64 <3.1.0.2365 | 1.0.0 up to, but not including, 3.1.0.2365 | 3.1.0.2365 |
| Beckhoff Automation | TcRouter.sys for Windows on x86 3.1.0.2364 | 3.1.0.2364 | Not stated |
| Beckhoff Automation | TcRouter.sys for Windows on x86 <3.1.0.2365 | 1.0.0 up to, but not including, 3.1.0.2365 | 3.1.0.2365 |
| Beckhoff Automation | TwinCAT.XAR.Base.KM 3.16.29 | 3.16.29 | Not stated |
| Beckhoff Automation | TwinCAT.XAR.Base.KM <3.18.1 | 1.0.0 up to, but not including, 3.18.1 | 3.18.1 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cert.vde.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.5 | High | CNA (cert.vde.com) |
| CVSS 3.1 | 7.8 | High | CNA (cert.vde.com) |
Official description
A local low privileged attacker or process can access I/O ports via TcRouter.sys because of exposed IOCTL function calls resulting in a full compromise of the affected devices.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Exposed IOCTL with Insufficient Access Control
The product implements an IOCTL with functionality that should be restricted, but it does not properly enforce access control for the IOCTL.
How developers prevent this class of flaw
- In Windows environments, use proper access control for the associated device or device namespace. See References.
More Exposed IOCTL with Insufficient Access Control vulnerabilities (CWE-782)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in TcRouter.sys for Windows on x64 3.1.0.2364
- 7.8 High severity
- 7.8 High severity
Recent Exposed IOCTL with Insufficient Access Control vulnerabilities
- 8.5 High severity
- 8.4 High severity
- 8.7 High severity
- 7.1 High severity
- 7.8 High severity
- 7.1 High severity
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