Full Report
Mendix SAML module contains a vulnerability that could allow unauthenticated remote attackers to hijack an account in specific SSO configurations. Mendix has provided fix releases for the Mendix SAML module and recommends to update to the latest version.
Analysis Summary
# Main Topic
**Mendix SAML Module Account Hijacking Vulnerability (CVE‑2026‑80465)**
An unauthenticated remote attacker can exploit improper validation of SAML response signatures in Mendix SAML modules (versions < V3.6.27 for Mendix 9.x and < V4.2.3 for Mendix 10/11) to hijack user accounts in specific Single Sign‑On (SSO) configurations.
## Key Points
- **Vulnerability**: Improper verification of cryptographic signatures (CWE‑347) allows session hijacking.
- **Impact**: Remote attackers can hijack accounts without authentication, leading to potential privilege escalation and data exfiltration.
- **Affected Versions**:
- Mendix 9.24 compatible: < V3.6.27
- Mendix 10 compatible: < V4.2.3
- Mendix 11 compatible: < V4.2.3
- **CVSS Scores**:
- v3.1: 8.7 (AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N)
- v4.0: 8.8 (AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N)
- **Fix**: Mendix released patch versions (V3.6.27 or later, V4.2.3 or later).
## Threat Actors
- **Attribution**: Not disclosed; vulnerability appears to be a security flaw rather than a targeted campaign.
- **Motivation**: Potential for unauthorized access and exploitation of sensitive data via hijacked accounts.
## TTPs
- **Technique**: Improper verification of cryptographic signatures in SAML responses.
- **MITRE ATT&CK**:
- T1606.001 – Compromise or Abuse Authentication: “SAML Tokens”
- T1078 – Valid Accounts (post‑hijack)
## Affected Systems
- Mendix SAML modules integrated into enterprise applications:
- Mendix 9.x (versions < V3.6.27)
- Mendix 10.x (versions < V4.2.3)
- Mendix 11.x (versions < V4.2.3)
- Systems relying on SSO via these modules, particularly those using specific configurations that do not enforce signature validation.
## Mitigations
- **Patch**: Upgrade the Mendix SAML module to the latest version (≥ V3.6.27 for Mendix 9.x, ≥ V4.2.3 for Mendix 10/11).
- Defanged download link: `hxxps://marketplace[.]mendix[.]com/link/component/1174`
- **Configuration**: Ensure that SAML responses are signed and that signature validation is enforced.
- **Network Controls**: Restrict network access to the SAML endpoint per Siemens’ Industrial Security guidelines.
- Defanged guideline link: `hxxps://www[.]siemens[.]com/cert/operational-guidelines-industrial-security`
- **Monitoring**: Log SAML authentication attempts and monitor for anomalous session hijacking patterns.
## Conclusion
The CVE‑2026‑80465 vulnerability presents a high‑severity risk for organizations using Mendix SAML modules in SSO environments. Immediate patching to the specified versions and stringent signature validation are essential to mitigate the risk of account hijacking. Continuous monitoring and adherence to Siemens’ security recommendations will further reduce potential exploitation.