CVE-2026-53904 PUBLISHED

Account Denial of Service in MCO

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

MCO is vulnerable to Account Denial of Service due to improper implementation of password reset functionality. Each password reset request invalidates previously set password as well as previously issued temporary passwords, furthermore, password resets are not limited in any way. An attacker who provides victim's email and answer to their security question, can successfully initiate the reset process and continuously invalidate credentials, effectively locking the victim out of their account. Answering security questions has a limited number of tries which lowers the risk of this vulnerability.

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:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CVSS Score: 6.3

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-307 Improper Restriction of Excessive Authentication Attempt CWE
  • CWE-640 Weak Password Recovery Mechanism for Forgotten Password CWE

Impacts

  • CAPEC-2 Inducing Account Lockout