Siemens Opcenter X
Summary
<p><a href="https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-202-03.json"><strong>View CSAF</strong></a></p> <h2>Summary</h2> <p><strong>Opcenter X before V2604 contain an authentication bypass vulnerability that could allow an attacker to gain full unauthorized access to the application. Siemens has released a new version for Opcenter X and recommends to update to the latest version.</strong></p> <p>The following versions of Siemens Opcenter X are affected:</p> <ul> <li>Opcenter X vers:intdot/<2604</li> </ul> <div class="csaf-table"> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>CVSS</th> <th>Vendor</th> <th>Equipment</th> <th>Vulnerabilities</th> </tr> </thead> <tbody> <tr> <td>v3 10</td> <td>Siemens</td> <td>Siemens Opcenter X</td> <td>Improper Verification of Cryptographic Signature</td> </tr> </tbody> </table> </div> <h3>Background</h3> <ul> <li><strong>Critical Infrastructure Sectors: </strong>Critical Manufacturing</li> <li><strong>Countries/Areas Deployed: </strong>Worldwide</li> <li><strong>Company Headquarters Location: </strong>Germany</li> </ul> <hr /> <h2>Vulnerabilities</h2> <div class="csaf-accordion"> <p><a class="csaf-accordion-toggle-all" href="https://www.cisa.gov/">Expand All +</a></p> <div class="csaf-accordion-item"> <h3><a class="csaf-accordion-toggle" href="https://www.cisa.gov/">CVE-2026-56451</a></h3> <div class="csaf-accordion-content"> <p>Affected applications do not properly validate the algorithm specified in the JSON Web Token (JWT) header. This could allow an unauthenticated remote attacker to forge arbitrary JWT, bypass authentication mechanisms and impersonate any user including administrative accounts, potentially gaining full unauthorized access to the application.</p> <p><a href="https://www.cve.org/CVERecord?id=CVE-2026-56451">View CVE Details</a></p> <hr /> <h4>Affected Products</h4> <h5>Siemens Opcenter X</h5> <div class="ics-vendor-version-status"> <div class="ics-vendor"><strong>Vendor:</strong><br />Siemens</div> <div class="ics-version"><strong>Product Version:</strong><br />Opcenter X < V2604</div> <div class="ics-status"><strong>Product Status:</strong><br />known_affected</div> </div> <div class="ics-remediations"> <h6>Remediations</h6> <p><strong>Vendor fix</strong><br />Update to V2604 or later version<br /><a href="https://support.sw.siemens.com/product/206159703/">https://support.sw.siemens.com/product/206159703/</a></p> </div> <p><strong>Relevant CWE:</strong> <a href="https://cwe.mitre.org/data/definitions/347.html">CWE-347 Improper Verification of Cryptographic Signature</a></p> <hr /> <h4>Metrics</h4> <div class="csaf-table csaf-metrics-table"> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>CVSS Version</th> <th>Base Score</th> <th>Base Severity</th> <th>Vector String</th> </tr> </thead> <tbody> <tr> <td>3.1</td> <td>10</td> <td>CRITICAL</td> <td><a href="https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H">CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H</a></td> </tr> </tbody> </table> </div> </div> </div> </div> <hr /> <h2>Acknowledgments</h2> <ul> <li>Siemens ProductCERT reported this vulnerability to CISA.</li> </ul> <hr /> <h2>General Recommendations</h2> <p>As a general security measure, Siemens strongly recommends to protect network access to devices with appropriate mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends to configure the environment according to Siemens' operational guidelines for Industrial Security (Download: https://www.siemens.com/cert/operational-guidelines-industrial-security), and to follow the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity</p> <hr /> <h2>Additional Resources</h2> <p>For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT: https://www.siemens.com/cert/advisories</p> <hr /> <h2>Terms of Use</h2> <p>The use of Siemens Security Advisories is subject to the terms and conditions listed on: https://www.siemens.com/productcert/terms-of-use.</p> <hr /> <h2>Legal Notice and Terms of Use</h2> <p>This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy).</p> <hr /> <h2>Recommended Practices</h2> <p>CISA recommends users take defensive measures to minimize the exploitation risk of these vulnerabilities.</p> <p>Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the internet.</p> <p>Locate control system networks and remote devices behind firewalls and isolate them from business networks.</p> <p>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.</p> <p>CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.</p> <p>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.</p> <p>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.</p> <p>Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.</p> <hr /> <h2>Advisory Conversion Disclaimer</h2> <p>This ICSA is a verbatim republication of Siemens ProductCERT SSA-096828 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.</p> <h2>Revision History</h2> <ul> <li><strong>Initial Release Date: </strong>2026-07-14</li> </ul> <table class="tablesaw tablesaw-stack"> <thead> <tr> <th>Date</th> <th>Revision</th> <th>Summary</th> </tr> </thead> <tbody> <tr> <td>2026-07-14</td> <td>1</td> <td>Publication Date</td> </tr> <tr> <td>2026-07-21</td> <td>2</td> <td>Initial CISA Republication of Siemens ProductCERT SSA-096828 advisory</td> </tr> </tbody> </table> <hr /> <h2>Legal Notice and Terms of Use</h2>