CVE-2026-89209
MediumCVSS 6.8Exploitation Probability (EPSS)
Low risk18th percentile - higher than 18% of all known CVEs
Summary
The Mendix SAML module (Mendix 9, 10, and 11 compatible versions before V3.6.29 and V4.2.4 respectively) does not properly protect against SAML assertion replay in IdP-initiated authentication flows. This could allow unauthenticated remote attackers to gain unauthorized access by replaying a valid SAML response.
Risk Assessment
An attacker can capture a valid SAML assertion and replay it to gain access to the application without valid credentials. This poses a significant risk to the confidentiality and integrity of protected resources.
Recommendation
Update the Mendix SAML module to V4.2.4 (for Mendix 10/11) or V3.6.29 (for Mendix 9) or later. Verify replay protection configuration on both the IdP and SP sides.
Other vulnerabilities in Mendix SAML
See all- CVE-2023-29129Critical
The Mendix SAML module in multiple versions insufficiently verifies SAML assertions. This could allow unauthenticated remote attackers to bypass authentication and gain access to the application. The vulnerability affects specific module versions for Mendix 7, 8, and 9.
- CVE-2023-25957Critical
The affected versions of the Mendix SAML module insufficiently verify SAML assertions. An unauthenticated remote attacker could bypass authentication and gain access to the application. For compatibility reasons, fixed versions still contain this issue, but only when the recommended default configuration option 'Use Encryption' is disabled.
- CVE-2026-80465High
The Mendix SAML module in versions before V4.2.4 (for Mendix 10 and 11) and before V3.6.29 (for Mendix 9.24) does not properly validate the SAML response signature. In specific SSO configurations, this could allow unauthenticated remote attackers to hijack an account or session.
Original NVD description (English source)
A vulnerability has been identified in Mendix SAML (Mendix 10 compatible) (All versions < V4.2.4), Mendix SAML (Mendix 11 compatible) (All versions < V4.2.4), Mendix SAML (Mendix 9 compatible) (All versions < V3.6.29). 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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS