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TI-2026-38879 Aliases CVE-2026-53903GHSA-h63w-8j45-g3cx

Insecure Direct Object Reference in MCO

Priority LOW 24CWE-639Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
Low · None · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-639.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00407 35th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MyComplianceOfficeMCO25.3.3.1—No fix listedCNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mycomplianceoffice:mycomplianceoffice:25.3.3.1:*:*:*:*:*:*:*25.3.3.1VulnerableMyComplianceOffice
  • cpe:2.3:a:mycomplianceoffice:mycomplianceoffice:25.3.3.1:*:*:*:*:*:*:* Versions 25.3.3.1 Vulnerable ·MyComplianceOffice

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-53903
  2. 2026-10-03 Alias added: GHSA-h63w-8j45-g3cx

References

Advisory 1

Other 1

  • TI-2026-38884 User Enumeration in MCO CVSS 4.0MEDIUM 6.9
  • TI-2026-38878 Privilege Escalation in MCO CVSS 4.0HIGH 7.1
  • TI-2026-38885 Arbitrary File Upload in MCO CVSS 4.0MEDIUM 5.3
  • TI-2026-38882 Path Disclosure and Path Traversal in MCO CVSS 4.0MEDIUM 5.1
  • TI-2026-38881 Unauthorized Access to Administrator ACL View in MCO CVSS 4.0MEDIUM 5.3
  • TI-2026-38883 Stored Cross‑Site Scripting in MCO CVSS 4.0MEDIUM 4.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences