Original Article Summary

View CSAF Summary Successful exploitation of this vulnerability could allow a malicious user the ability to deliver malicious firmware that can update and gain full control of the controller. The following versions of Watchfire Controller Software are affected: BC550 12.30 (CVE-2026-5846) BC750 11.33|12.35 (CVE-2026-5846) BC760 12.38|13.00 (CVE-2026-5846) BC760DC 12.39 (CVE-2026-5846) CVSS Vendor Equipment Vulnerabilities v3 5.7 Watchfire Watchfire Controller Software Use of Hard-coded Cryptographic Key Background Critical Infrastructure Sectors: Commercial Facilities, Critical Manufacturing, Healthcare and Public Health, Financial Services Countries/Areas Deployed: United States, Dominican Republic, Canada, Peru, El Salvador Company Headquarters Location: United States Vulnerabilities Expand All + CVE-2026-5846 The affected product contains self-signed hard-coded RSA private keys and corresponding X.509 certificates used for authenticating and encrypting HTTPS/TLS connections to the controller's built-in web management interface. These keys are embedded in plaintext within the application patch binaries in the firmware directly from Watchfire's Remote Support filestore. View CVE Details Affected Products Watchfire Controller Software Vendor: Watchfire Product Version: Watchfire BC550: 12.30, Watchfire BC750: 11.33|12.35, Watchfire BC760: 12.38|13.00, Watchfire BC760DC: 12.39 Product Status: known_affected Remediations Mitigation Watchfire has applied the required security patch to all affected controllers under its management. Watchfire recommends users verify their controller software version and upgrade to one of the approved versions below, if they are not already on an approved patch level. Vendor fix Watchfire has issued patches to disable the use of the existing certificate as follows: BC550 12.30: Patch to 12.31 SP1BC750 11.33: Patch to 11.34BC750 12.35: Patch to 12.36 SP1BC760 12.38: Patch to 12.41 SP1BC760 13.00: Patch to 14.00 SP1BC760DC 12.39: Patch to 12.41 SP1 Relevant CWE: CWE-321 Use of Hard-coded Cryptographic Key Metrics CVSS Version Base Score Base Severity Vector String 3.1 5.7 MEDIUM CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:N 4.0 7.6 HIGH CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N Acknowledgments James Tillson 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. CISA also recommends users take the following measures to protect themselves from social engineering attacks: Do not click web links or open attachments in unsolicited email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploitation specifically targeting this vulnerability has been reported to CISA at this time. This vulnerability has a high attack complexity. Revision History Initial Release Date: 2026-07-30 Date Revision Summary 2026-07-30 1 Initial Publication Legal Notice and Terms of Use