← Vulnerability feed

Vulnerability record · CVE-2026-53903 · published 1 July 2026

CVE-2026-53903: Mycomplianceoffice insecure direct object reference vulnerability

Mycomplianceoffice · Mycomplianceoffice

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.

5.3 CVSS 4.0 Medium EPSS 0.41% · top 67.7% CWE-639 · Insecure direct object reference
5.3CVSS 4.0 base score
0.41%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
6 Jul 2026Last modified by NVD

Description

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:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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

Track CVE-2026-53903 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.1CVE-2026-53902Mycomplianceoffice incorrect authorization vulnerabilityMCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/profile-sections/group-membership endpoint. An authenticated u…EPSS 0.34%6.9CVE-2026-53908Mycomplianceoffice vulnerabilityMCO is vulnerable to User Enumeration through authentication-related functionalities. The application returns distinguishable responses for valid and…EPSS 0.36%5.3CVE-2026-53909Mycomplianceoffice unrestricted file upload vulnerabilityMCO does not correctly validate types of uploaded files. File upload validation functionality relies only on client-side checks, which can be bypasse…EPSS 0.39%5.3CVE-2026-53905Mycomplianceoffice incorrect authorization vulnerabilityMCO does not properly enforce authorization checks in the /customer/servlet/mco/webapi/admin-view-hierarchy/get-acl-tree-structure endpoint. An authe…EPSS 0.32%5.1CVE-2026-53906Mycomplianceoffice path traversal vulnerabilityMCO is vulnerable to Path Disclosure and Path Traversal in file handling functionality related to data export and upload. Improper validation of the …EPSS 0.52%4.8CVE-2026-53907Mycomplianceoffice cross-site scripting vulnerabilityMCO is vulnerable to Stored Cross‑Site Scripting (XSS) via the application logo upload functionality. An attacker with the ability to change the appl…EPSS 0.24%8.4CVE-2026-55255Langflow IDOR in responses endpoint allows cross-user flow executionLangflow before 1.9.1 has an insecure direct object reference in the /api/v1/responses endpoint. An authenticated attacker can supply another user's …KEVEPSS 0.89%analysed

Source: NIST National Vulnerability Database (record CVE-2026-53903), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.