Horner Automation Cscape and XL4, XL7 PLC Weak Password Vulnerability
Summary
CISA ICS-CERT published an advisory for Horner Automation Cscape and XL4, XL7 PLCs (CVSS 9.1 CRITICAL) identifying weak password requirements vulnerability. Affected versions include Cscape v10.0, XL7 PLC v15.60, and XL4 PLC v16.32.0. An attacker with network access could brute force discover passwords to gain unauthorized access to systems and services. Vendor fix is available: update to Cscape v10.2 SP2 or later and latest firmware.
What changed
CISA ICS-CERT published advisory ICSA-26-106-02 identifying a critical vulnerability (CVE-2026-6284, CVSS 9.1) in Horner Automation Cscape and XL4, XL7 PLCs. The vulnerability stems from weak password requirements (CWE-521) with no password input limiters, allowing attackers with network access to brute force discover passwords and gain unauthorized system access.
Organizations using affected Horner Automation products should update to Cscape v10.2 SP2 or later and apply the latest firmware updates for XL4 and XL7 PLCs. CISA recommends minimizing network exposure for control system devices, isolating control networks behind firewalls, and using secure remote access methods such as VPNs when remote access is required. No known public exploitation targeting this vulnerability has been reported.
Archived snapshot
Apr 17, 2026GovPing captured this document from the original source. If the source has since changed or been removed, this is the text as it existed at that time.
ICS Advisory
Horner Automation Cscape and XL4, XL7 PLC
Release Date
April 16, 2026
Alert Code ICSA-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
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.
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 fix
Horner 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/
Mitigation
For 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
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