CVE-2026-53904
Account Denial of Service in MCO
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Account Denial of Service in MCO
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.
- Record
CVE-2026-53904- CVSS 4.0
- 6.3 Medium
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 - Weakness
- CWE-307, CWE-640
- Updated
- 2026-11-02
EUVDEUVD-2026-40950
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.
- Record
EUVD-2026-40950- CVSS 4.0
- 6.3 Medium
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4p9c-w7qw-q5pq
MCO is vulnerable to Account Denial of Service due to improper implementation of password reset...
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.
- Record
GHSA-4p9c-w7qw-q5pq- CVSS 4.0
- 6.3 Medium
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H - Weakness
- CWE-307
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-53904- CVSS 4.0
- 6.3 Medium
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H - Weakness
- CWE-307, CWE-640
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-53904 is a medium vulnerability (CVSS 6.3) in Mycomplianceoffice Mco, published July 1, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.34%, the 27th percentile. No source names a fixed version.