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TI-2026-38884 Aliases CVE-2026-53908GHSA-59mp-p3m2-6wr7

User Enumeration in MCO

Priority LOW 36CWE-204Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Information disclosure
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-204.

Summary

MCO is vulnerable to User Enumeration through authentication-related functionalities. The application returns distinguishable responses for valid and invalid users during username reminder and password reset operations. An attacker can leverage these differences to enumerate valid usernames and email addresses. 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 0.00361 30th 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
Yes
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-2026-53908
  2. 2026-10-03 Alias added: GHSA-59mp-p3m2-6wr7

References

  • 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-2026-38879 Insecure Direct Object Reference in MCO CVSS 4.0MEDIUM 5.3
  • TI-2026-38883 Stored Cross‑Site Scripting in MCO CVSS 4.0MEDIUM 4.8

Sources