CVE-2026-53908 PUBLISHED

User Enumeration in MCO

Assigner: CERT-PL
Reserved: 11.06.2026 Published: 01.07.2026 Updated: 01.07.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 6.9

Product Status

Vendor MyComplianceOffice
Product MCO
Versions Default: unknown
  • Version 25.3.3.1 is affected

Credits

  • Hubert Decyusz (AFINE Team) finder

References

Problem Types

  • CWE-204 Observable Response Discrepancy CWE