Vulnerability Details CVE-2026-53903
MCO is vulnerable to an Insecure Direct Object Reference (IDOR) vulnerability in the /customer/servlet/mco/webapi/trading-document/fetchPdfStatement endpoint. The application does not properly validate whether an authenticated user is authorized to access a requested document, allowing direct retrieval based on a user-supplied identifier.
An attacker can access trading documents belonging to other users by providing a valid document ID. Although exploitation requires guessing the identifier, predictable ID patterns enable feasible enumeration, leading to unauthorized disclosure of sensitive information.
Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 15.9%
CVSS Severity
CVSS v3 Score 8.1
Products affected by CVE-2026-53903
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cpe:2.3:a:mycomplianceoffice:mycomplianceoffice:25.3.3.1