# CVE-2026-53903: MyComplianceOffice MCO IDOR in fetchPdfStatement

Source: https://junglewise.ai/threats/cve-2026-53903-mycomplianceoffice-mco-idor-in-fetchpdfstatement  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-01. Updated: 2026-07-01  
License: CC BY 4.0 with a link back

CVE-2026-53903 · Severity: info · CVSS 5.3 · Published 2026-07-01

MyComplianceOffice (MCO) is a compliance management platform used by financial services and insurance firms to manage regulatory obligations and trading documents. A security flaw allows an authenticated user to access the private trading documents and PDF statements of other users by manipulating document identifiers in the web address. This could lead to the unauthorized disclosure of sensitive financial information and personal data belonging to other customers.

Technologies: [MyComplianceOffice MCO](https://junglewise.ai/threats/technologies/mco). Vendors: [MyComplianceOffice](https://junglewise.ai/threats/vendors/mycomplianceoffice).

## Quick answers

**Is CVE-2026-53903 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-53903 being exploited in the wild.

**How severe is CVE-2026-53903?** Informational severity, with a CVSS score of 5.3, published 1 July 2026.

**Which products and versions are affected?** MyComplianceOffice MCO 25.3.3.1.

**Is there a fix for CVE-2026-53903?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-53903 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-53903?** Check whether you run MyComplianceOffice MCO at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An Insecure Direct Object Reference (IDOR) vulnerability exists in the `/customer/servlet/mco/webapi/trading-document/fetchPdfStatement` endpoint of MyComplianceOffice (MCO). The application fails to perform adequate authorization checks to ensure that the requesting authenticated user has the rights to view a specific document. An attacker can supply a different document identifier to retrieve PDF statements belonging to other users. While exploitation requires knowledge of valid document IDs, the advisory notes that predictable ID patterns make enumeration feasible. The vulnerability is confirmed in version 25.3.3.1; vendor contact was unsuccessful, so patch status is unconfirmed.

## Affected products

- MyComplianceOffice MCO 25.3.3.1

## Timeline

- 2026-07-01: disclosed: Vulnerability disclosed by CERT Polska
- 2026-07-01: advisory

## References

- [https://cert.pl/en/posts/2026/07/CVE-2026-53902](https://cert.pl/en/posts/2026/07/CVE-2026-53902)
- [https://mco.mycomplianceoffice.com/](https://mco.mycomplianceoffice.com/)

## Related threats

- [MyComplianceOffice MCO Unrestricted File Upload](https://junglewise.ai/threats/cve-2026-53909-mycomplianceoffice-mco-unrestricted-file-upload)
- [MyComplianceOffice MCO user enumeration in authentication components](https://junglewise.ai/threats/cve-2026-53908-mycomplianceoffice-mco-user-enumeration-in-authentication)
- [MyComplianceOffice MCO Stored XSS in logo upload](https://junglewise.ai/threats/cve-2026-53907-mycomplianceoffice-mco-stored-xss-in-logo-upload)
- [MyComplianceOffice MCO path traversal and path disclosure in file handling](https://junglewise.ai/threats/cve-2026-53906-mycomplianceoffice-mco-path-traversal-and-path-disclosure-in-file)
- [MyComplianceOffice MCO Incorrect Authorization in ACL Tree Endpoint](https://junglewise.ai/threats/cve-2026-53905-mycomplianceoffice-mco-incorrect-authorization-in-acl-tree)