Account hijacking via improper SAML signature validation
Published Sep 3, 2026 · Updated Sep 3, 2026
Improper signature validation in Siemens Mendix SAML before 4.2.3 or 3.6.27 allows remote attackers to hijack account sessions. The module accepts SAML responses without properly validating their cryptographic signatures before establishing the associated application session. Exploitation requires a specific SSO configuration; a successful request grants access under the hijacked account without interrupting service.
Summary
What happened
Improper signature validation in Siemens Mendix SAML before 4.2.3 or 3.6.27 allows remote attackers to hijack account sessions. The module accepts SAML responses without properly validating their cryptographic signatures before establishing the associated application session. Exploitation requires a specific SSO configuration; a successful request grants access under the hijacked account without interrupting service.
The record
- CVE
- CVE-2026-80465
- Published
- Sep 3, 2026
- Updated
- Sep 3, 2026
- Vendor
- Siemens
- Product
- Mendix SAML
- Classifications
- CWE-347, T1606.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 3, 2026CVE publishedPublication date reported by the CVE source.
- Sep 3, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <V3.6.27
- Affected versionversion=0 <V4.2.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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