Siemens Mendix SAML Module
Siemens Mendix SAML module vulnerable to authentication bypass via SAML assertion replay.
A critical authentication bypass vulnerability (CVE-2026-89209) has been discovered in Siemens' Mendix SAML module. The flaw allows unauthenticated remote attackers to gain unauthorized access by replaying a valid SAML assertion in IdP-initiated authentication flows. Siemens has released updated versions of the affected Mendix SAML modules and recommends immediate patching.
AI summary of the linked source. Not reviewed by an editor. How this works
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The lesson from this incident
Full lessonA critical authentication bypass flaw in the Siemens Mendix SAML module allows unauthenticated attackers to replay valid SAML assertions and gain unauthorized access without credentials, effectively undermining the entire authentication layer. The root cause lies in insufficient validation of SAML assertions during IdP-initiated flows, a well-understood class of vulnerability that should be caught during both development and routine security review. This matters because SAML is a foundational identity federation protocol — bypassing it can grant attackers the same access level as legitimate users, including administrators. Siemens has released patches, making delayed adoption the primary remaining risk for affected organizations.
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- Phishing-resistant MFA
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- Identity threat detection and response (ITDR)
Attackers who log in with real, stolen credentials get noticed.
- Automated patch management
Known holes get closed in days, not months.
Indicators of Compromise
Extracted by AI from the linked source. Not reviewed by an editor. How this works
- cve — CVE-2026-89209