CVE-2026-53904CWE-307CWE-640

Account Denial of Service in MCO

Medium · published July 1, 2026

CVSS v4.0
6.3
EPSS
0%
Percentile
26.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
6.3 · MEDIUM
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
EPSS
0.00341 · 26.4th percentile
Weaknesses
CWE-307 · Improper Restriction of Excessive Authentication Attempts; CWE-640 · Weak Password Recovery Mechanism for Forgotten Password
Published
2026-07-01T11:58Z
EPSS history
Timeline
  • 01 JUL 11:58Z
    Account Denial of Service in MCO
    cvelistv5