CVE-2026-53904: medium-severity vulnerability in MyComplianceOffice MCO
Account Denial of Service in MCO
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.3epss 0.3%
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.
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
Affected products
MyComplianceOffice · MCORelated CVEs — MyComplianceOffice MCO
In the same product, most dangerous first.
CVE-2026-53906MEDIUMPath Disclosure and Path Traversal in MCOEPSS 0.5%CVE-2026-53903MEDIUMInsecure Direct Object Reference in MCOEPSS 0.4%CVE-2026-53909MEDIUMArbitrary File Upload in MCOEPSS 0.4%CVE-2026-53908MEDIUMUser Enumeration in MCOEPSS 0.4%CVE-2026-53902HIGHPrivilege Escalation in MCOEPSS 0.3%CVE-2026-53905MEDIUMUnauthorized Access to Administrator ACL View in MCOEPSS 0.3%