Summary
Successful exploitation of this vulnerability could allow an attacker to gain full system control and misuse it to access or manipulate connected networks and resources.
The following versions of Toptech Systems RCU II+ and Multiload II+ are affected:
- RCU II+
- Multiload II+
| CVSS | Vendor | Equipment | Vulnerabilities |
|---|---|---|---|
| v3 8.8 | Toptech Systems | Toptech Systems RCU II+ and Multiload II+ | Missing Authentication for Critical Function |
Background
- Critical Infrastructure Sectors: Energy
- Countries/Areas Deployed: Worldwide
- Company Headquarters Location: United States
Vulnerabilities
CVE-2026-12562
The RCU II+ and Multiload II+ are vulnerable to an unauthenticated service that exposes a debug interface granting full root-level access to the embedded system. This vulnerability stems from a network-accessible port running a Target Communications Framework (TCF) service that does not require any authentication, allowing an attacker to directly interact with the Linux environment that powers the device. Once connected, an attacker can freely view and modify the filesystem, manipulate running processes, and control network interfaces, enabling deep alteration of system behavior.
Affected Products
Toptech Systems RCU II+ and Multiload II+
Toptech Systems
Toptech Systems RCU II+:
known_affected
Remediations
Mitigation
Toptech Systems provides two methods for remediating affected RCU II+ and Multiload II+ units: First, move the device to a closed or segmented network without untrusted access.
Mitigation
Run one of the RCU II+/Multiload II+ Vulnerability Removal Tools (VRT) available at https://s3.amazonaws.com/docs.toptech.com/nonpublic/rcuiip_mliip_vrt.zip, https://s3.amazonaws.com/docs.toptech.com/nonpublic/rcuiip_mliip_vrt.gz. *-* This option does not require breaking Weights and Measures seals and has the least operational impact.
https://s3.amazonaws.com/docs.toptech.com/nonpublic/rcuiip_mliip_vrt.zip
Mitigation
Run one of the RCU II+/Multiload II+ Vulnerability Removal Tools (VRT) available at https://s3.amazonaws.com/docs.toptech.com/nonpublic/rcuiip_mliip_vrt.zip, https://s3.amazonaws.com/docs.toptech.com/nonpublic/rcuiip_mliip_vrt.gz. *-* This option does not require breaking Weights and Measures seals and has the least operational impact.
https://s3.amazonaws.com/docs.toptech.com/nonpublic/rcuiip_mliip_vrt.gz
Mitigation
This option does not require breaking Weights and Measures seals and has the least operational impact.
Mitigation
Install the latest firmware from https://s3.amazonaws.com/docs.toptech.com/index.html#downloads/Firmware/RCUII+_MLII+_SMPII+/. *-* This method requires stopping the bay and breaking the W&M seal. Be sure to back up the current ML configuration before performing the firmware update.
https://s3.amazonaws.com/docs.toptech.com/index.html#downloads/Firmware/RCUII+_MLII+_SMPII+/
Mitigation
This method requires stopping the bay and breaking the W&M seal. Be sure to back up the current ML configuration before performing the firmware update.
Mitigation
For questions, contact Toptech Systems Support at security@toptech.com. Additional details are available in Toptech System's firmware vulnerability notice: https://s3.amazonaws.com/docs.toptech.com/nonpublic/2025%2012%2001%20RCU%20IIPlus%20MultiLoad%20IIPlus%20Vulnerability%20Notice.pdf.
mailto:security@toptech.com
Mitigation
For questions, contact Toptech Systems Support at security@toptech.com. Additional details are available in Toptech System's firmware vulnerability notice: https://s3.amazonaws.com/docs.toptech.com/nonpublic/2025%2012%2001%20RCU%20IIPlus%20MultiLoad%20IIPlus%20Vulnerability%20Notice.pdf.
https://s3.amazonaws.com/docs.toptech.com/nonpublic/2025%2012%2001%20RCU%20IIPlus%20MultiLoad%20IIPlus%20Vulnerability%20Notice.pdf
Relevant CWE: CWE-306 Missing Authentication for Critical Function
Metrics
| CVSS Version | Base Score | Base Severity | Vector String |
|---|---|---|---|
| 3.1 | 8.8 | HIGH | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 4.0 | 8.7 | HIGH | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
Acknowledgments
- Donald Green of Southwest Research Institute reported this vulnerability to CISA
Legal Notice and Terms of Use
This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy).
Recommended Practices
CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability.
Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet.
Locate control system networks and remote devices behind firewalls and isolating them from business networks.
When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.
CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets.
Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.
No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. This vulnerability is not exploitable remotely.
Revision History
- Initial Release Date: 2026-07-30
| Date | Revision | Summary |
|---|---|---|
| 2026-07-30 | 1 | Initial Publication |