What is CVE-2026-89209?

CVE-2026-89209 is a medium-severity vulnerability in Siemens Mendix Saml (Mendix 10 Compatible), classified under Authentication Bypass by Capture-replay. CVSS score: 6.8/10. Published 2026-10-26.

How severe is CVE-2026-89209?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Vulnerability in Siemens Mendix Saml (Mendix 10 Compatible)

CVE-2026-89209

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.

Published 2026-10-26 · last modified 2026-10-26.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

CWE-294 — Authentication Bypass by Capture-replay

References

cert-portal.siemens.com/productcert/html/ssa-137528.html

Frequently asked questions

What is CVE-2026-89209?: CVE-2026-89209 is a medium-severity vulnerability in Siemens Mendix Saml (Mendix 10 Compatible), classified under Authentication Bypass by Capture-replay. CVSS score: 6.8/10. Published 2026-10-26.
How severe is CVE-2026-89209?: Medium severity. CVSS v3 base score is 6.8 out of 10.