Siemens Mendix SAML Module

View CSAF Summary Mendix SAML module contains an authentication bypass vulnerability that could allow an unauthenticated remote attacker to gain unauthorized access by replaying a valid SAML assertion in IdP-initiated authentication flows. Siemens has released new versions for the affected products and recommends to update to the latest versions. The following versions of Siemens Mendix SAML Module are affected: Mendix SAML (Mendix 10 compatible) vers:intdot/<4.2.4 (CVE-2026-89209) Mendix SAML (Mendix 11 compatible) vers:intdot/<4.2.4 (CVE-2026-89209) Mendix SAML (Mendix 9 compatible) vers:intdot/<3.6.29 (CVE-2026-89209) CVSS Vendor Equipment v3 6.8 Siemens Mendix SAML (Mendix 10 compatible) 1 Vulnerability Authentication Bypass by Capture-replay Background Critical Infrastructure Sectors: Critical Manufacturing, Information Technology Countries/Areas Deployed: Worldwide Company Headquarters Location: Germany Vulnerabilities CVE-2026-89209 Affected versions of the module do not properly protect against SAML assertion replay in IdP-initiated authentication flows. This could allow unauthenticated remote attackers to gain unauthorized access to the application by replaying a valid SAML response. Read More 3 Affected Products Mendix SAML (Mendix 10 compatible) < V4.2.4 Product Status: known_affected Remediations Mitigation Disable IdP-initiated SSO Vendor fix Update to V4.2.4 or later version Mendix SAML (Mendix 11 compatible) < V4.2.4 Product Status: known_affected Remediations Mitigation Disable IdP-initiated SSO Vendor fix Update to V4.2.4 or later version Mendix SAML (Mendix 9 compatible) < V3.6.29 Product Status: known_affected Remediations Mitigation Disable IdP-initiated SSO Vendor fix Update to V3.6.29 or later version Additional Metrics Relevant CWE: CWE-294 Authentication Bypass by Capture-replay CVSS Version Base Score Base Severity Vector String 3.1 6.8 MEDIUM CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N View CVE Details Acknowledgments Siemens ProductCERT reported this vulnerability to CISA. General Recommendations 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 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. Recommended Practices CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. 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 Defe