Beckhoff TcRouter.sys: Exposed IOCTL allows local access to physical memory
Summary
Beckhoff TcRouter.sys, a Windows kernel driver of the TwinCAT 3 automation runtime, exposes IOCTL functions with insufficient access control. A local attacker with low privileges can access arbitrary physical memory or define its mapping, which can lead to full compromise of the affected device. Exploitation requires local access; the vulnerability is not remotely exploitable.
Affected
- TcRouter.sys for Windows x64 and x86: 3.1.0.2364 and versions from 1.0.0 before 3.1.0.2365
- TwinCAT.XAR.Base.KM: 3.16.29 and versions from 1.0.0 before 3.18.1
- Version ranges differ between sources; confirm against the CERT@VDE advisory.
Fixed in
- TcRouter.sys: 3.1.0.2365 or later (according to secondary sources; confirm with the vendor)
- TwinCAT.XAR.Base.KM: 3.18.1 or later (according to secondary sources; confirm with the vendor)
Workaround
Unknown. No vendor workaround is documented in the reviewed sources.
- Generic compensating controls, not vendor-documented: restrict local logon to trusted administrators, remove unneeded local accounts, and block known vulnerable drivers via the Windows driver blocklist or application control.
Exploitation
- Public exploit: none known (VulDB: no exploit available).
- In the wild: not known to be exploited.
- TcRouter.sys appears in the LOLDrivers catalogue, but that entry concerns a related TwinCAT driver and is not evidence for this CVE.
Our recommendation
- Check whether TwinCAT is installed on Windows industrial PCs, machine controllers and engineering workstations, and read the TcRouter.sys and TwinCAT.XAR.Base.KM versions.
- Update to TcRouter.sys 3.1.0.2365 or later and TwinCAT.XAR.Base.KM 3.18.1 or later, once confirmed in the Beckhoff advisory.
- Until patched, restrict local logon and driver loading to trusted administrators.
- Monitor affected hosts for unusual driver loads and privilege escalation.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CERT@VDE advisory VDE-2026-087 www.certvde.com
- CVE Record CVE-2026-18768 www.cve.org
- VulDB CVE-2026-18768 vuldb.com
- OffSeq listing CVE-2026-18768 radar.offseq.com
- LOLDrivers entry for TcRouter.sys www.loldrivers.io
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 10:22.
Original description (NVD)
A local low privileged attacker can access arbitrary physical memory or define its mapping via TcRouter.sys because of exposed IOCTL function calls resulting in a full compromise of the affected devices.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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