Siemens WTV676 and WTV776

CCISA Advisories · 5 hours ago

View CSAF Summary The products listed below contain a denial of service vulnerability that could allow an attacker to force the devices into protection mode under certain conditions. This disables remote connectivity functions (Web Access) to the devices. Siemens has released new versions for the affected products and recommends to update to the latest versions. The following versions of Siemens WTV676 and WTV776 are affected: WTV676-HB6035 Web Interface vers:intdot/<3.94 (CVE-2026-89207) WTV776-HB6035 Web Interface vers:intdot/<4.17 (CVE-2026-89207) CVSS Vendor Equipment Vulnerabilities v3 6.5 Siemens Siemens WTV676 and WTV776 Improper Validation of Specified Type of Input Background Critical Infrastructure Sectors: Energy Countries/Areas Deployed: Worldwide Company Headquarters Location: Germany Vulnerabilities Expand All + CVE-2026-89207 Affected devices do not properly validate input received from backend services. This could allow an unauthenticated remote attacker to force the device into protection mode, which results in losing remote connectivity functions (Web Access). View CVE Details Affected Products Siemens WTV676 and WTV776 Vendor:Siemens Product Version:WTV676-HB6035 Web Interface < V3.94, WTV776-HB6035 Web Interface < V4.17 Product Status:known_affected Remediations Vendor fixUpdate to V3.94 or later versionhttps://support.industry.siemens.com/cs/ww/en/view/109480838/ Vendor fixUpdate to V4.17 or later versionhttps://support.industry.siemens.com/cs/ww/en/view/109480838/ MitigationFor more information see the associated Siemens security advisory SSA-823812 in HTML and CSAF. Relevant CWE: CWE-1287 Improper Validation of Specified Type of Input Metrics CVSS Version Base Score Base Severity Vector String 3.1 6.5 MEDIUM CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L Acknowledgments Siemens ProductCERT reported this vulnerability to CISA. General Recommendations As a general security measure Siemens strongly recommends protecting network access to affected products with appropriate mechanisms. It is advised to follow recommended security practices in order to run the devices in a protected IT environment. Additional Resources For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT: https://www.siemens.com/cert/advisories  Terms of Use The use of Siemens Security Advisories is subject to the terms and conditions listed on: https://www.siemens.com/productcert/terms-of-use. 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 exploitation risk of these vulnerabilities. Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolate 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 recent version available. Also recognize VPN is only as secure as its 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. 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 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. Advisory Conversion Disclaimer This ICSA is a verbatim republication of Siemens ProductCERT SSA-823812 from a direct conversion of the vendor's Common Security Advisory Framework (CSAF) advisory. This is republished to CISA's website as a means of increasing visibility and is provided "as-is" for informational purposes only. CISA is not responsible for the editorial or technical accuracy of republished advisories and provides no warranties of any kind regarding any information contained within this advisory. Further, CISA does not endorse any commercial product or service. Please contact Siemens ProductCERT directly for any questions regarding this advisory. Revision History Initial Release Date: 2026-09-16 Date Revision Summary 2026-09-16 1 Publication Date 2026-09-22 2 Initial CISA Republication of Siemens ProductCERT SSA-823812 advisory Legal Notice and Terms of Use