CVE-2026-89209: Siemens Mendix SAML (Mendix 10 compatible) · Authentication Bypass by Capture-replay
Affects Siemens Mendix SAML (Mendix 10 compatible)Source CVE Database V5
Not known to be exploited · CVSS 6.8 Medium : upgrade to 4.2.4 when convenient.
Data as of 26 Oct 2026, 10:54 UTC
- Patch
- Available – fixed in 4.2.4, 3.6.29
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 26 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 24 Oct 2026.
What to do
Upgrade Mendix SAML (Mendix to 4.2.4 (10 compatible), 11 compatible)) or 3.6.29 (9 compatible)).
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| SiemensMendix SAML (Mendix 10 compatible) | Affected
| Fixed in
|
| SiemensMendix SAML (Mendix 11 compatible) | Affected
| Fixed in
|
| SiemensMendix SAML (Mendix 9 compatible) | Affected
| Fixed in
|
AI-suggested
Upgrade affected Mendix SAML modules to version 3.6.29 or 4.2.4 or later, where the vulnerability is fixed. No other mitigation or temporary workaround is indicated. Applying the official fix fully addresses the issue.
Description
CVE-2026-89209 is an authentication bypass vulnerability in Siemens Mendix SAML modules for Mendix 9, 10, and 11 compatible versions prior to 3.6.29 and 4.2.4 respectively. The flaw allows unauthenticated remote attackers to replay valid SAML assertions in IdP-initiated authentication flows, potentially gaining unauthorized access to applications.