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.

CVSS v3 8.1 HIGH

8.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://cert.pl/en/posts/2026/07/CVE-2026-53902	Third Party Advisory
https://mco.mycomplianceoffice.com/	Product

Configurations

Configuration 1 (hide)

cpe:2.3:a:mycomplianceoffice:mycomplianceoffice:25.3.3.1:*:*:*:*:*:*:*

History

06 Jul 2026, 17:33

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 8.1
First Time		Mycomplianceoffice mycomplianceoffice Mycomplianceoffice
References	~~() https://cert.pl/en/posts/2026/07/CVE-2026-53902 -~~	() https://cert.pl/en/posts/2026/07/CVE-2026-53902 - Third Party Advisory
References	~~() https://mco.mycomplianceoffice.com/ -~~	() https://mco.mycomplianceoffice.com/ - Product
CPE		cpe:2.3:a:mycomplianceoffice:mycomplianceoffice:25.3.3.1:::::::*

01 Jul 2026, 13:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-01 13:17

Updated : 2026-07-06 17:33

NVD link : CVE-2026-53903

Mitre link : CVE-2026-53903

CVE.ORG link : CVE-2026-53903

JSON object : View

Products Affected

mycomplianceoffice

mycomplianceoffice

CWE

CWE-639

Authorization Bypass Through User-Controlled Key

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