CVE-2026-53908: User Enumeration in MCO
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.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-53908?
CVE-2026-53908 has a medium severity rating of 6.9 according to the CVSS score.
How does CVE-2026-53908 affect MCO?
CVE-2026-53908 allows for user enumeration through distinguishable responses in authentication-related functionalities.
How can I mitigate CVE-2026-53908 in MCO?
To mitigate CVE-2026-53908, implement consistent response messages for both valid and invalid usernames during authentication processes.
What kind of attacks can CVE-2026-53908 enable?
CVE-2026-53908 can enable attackers to enumerate valid usernames and email addresses through the application's detailed error messaging.
When was CVE-2026-53908 published?
CVE-2026-53908 was published on July 1, 2026.