Horner Automation Cscape and XL4, XL7 PLC

Summary

Horner Automation Cscape v10.0, XL4 PLC v16.32.0, and XL7 PLC v15.60 contain a critical vulnerability (CVE-2026-6284) with a CVSS score of 9.1 that allows network-accessible attackers to brute-force discover weak passwords due to limited password complexity and no input rate limiting. The vulnerability affects critical manufacturing infrastructure worldwide and requires immediate patching to Cscape v10.2 SP2 or later and latest firmware for XL4/XL7 PLCs. No known public exploitation has been reported at the time of disclosure.

Full text

ICS Advisory Horner Automation Cscape and XL4, XL7 PLC Release DateApril 16, 2026 Alert CodeICSA-26-106-02 Related topics: Industrial Control System Vulnerabilities, Industrial Control Systems View CSAF Summary Successful exploitation of this vulnerability could allow an attacker to gain unauthorized access to systems and services. The following versions of Horner Automation Cscape and XL4, XL7 PLC are affected: Cscape v10.0 XL7 PLC v15.60 XL4 PLC v16.32.0 CVSS Vendor Equipment Vulnerabilities v3 9.1 Horner Automation Horner Automation Cscape and XL4, XL7 PLC Weak Password Requirements Background Critical Infrastructure Sectors: Critical Manufacturing Countries/Areas Deployed: Worldwide Company Headquarters Location: United States Vulnerabilities Expand All + CVE-2026-6284 An attacker with network access to the PLC is able to brute force discover passwords to gain unauthorized access to systems and services. The limited password complexity and no password input limiters makes brute force password enumeration possible. View CVE Details Affected Products Horner Automation Cscape and XL4, XL7 PLC Vendor:Horner Automation Product Version:Horner Automation Cscape: v10.0, Horner Automation XL7 PLC: v15.60, Horner Automation XL4 PLC: v16.32.0 Product Status:known_affected Remediations Vendor fixHorner Automation recommends users update to Cscape v10.2 SP2 or later. Horner Automation has also released the latest firmware for both XL4 and XL7 PLCs. Horner recommends users update to the latest version of the firmware. https://hornerautomation.com/cscape-software-free/cscape-software/.https://hornerautomation.com/cscape-software-free/cscape-software/ MitigationFor more information, see Horner Automation's release notes. Relevant CWE: CWE-521 Weak Password Requirements Metrics CVSS Version Base Score Base Severity Vector String 3.1 9.1 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Acknowledgments An anonymous researcher 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. Revision History Initial Release Date: 2026-04-16 Date Revision Summary 2026-04-16 1 Initial Publication Legal Notice and Terms of Use This product is provided subject to this Notification and this Privacy & Use policy. Vendor Horner Automation Tags Sector: Critical Manufacturing Sector Topics: Industrial Control System Vulnerabilities, Industrial Control Systems Please share your thoughts We recently updated our anonymous product survey; we welcome your feedback. Related Advisories Apr 16, 2026 ICS Advisory | ICSA-26-106-04 AVEVA Pipeline Simulation Apr 16, 2026 ICS Advisory | ICSA-26-106-03 Anviz Multiple Products Apr 16, 2026 ICS Advisory | ICSA-26-106-01 Delta Electronics ASDA-Soft Apr 09, 2026 ICS Advisory | ICSA-26-099-02 GPL Odorizers GPL750

Indicators of Compromise

• cve — CVE-2026-6284

Entities