# CVE-2026-53908: MyComplianceOffice MCO user enumeration in authentication components

Source: https://junglewise.ai/threats/cve-2026-53908-mycomplianceoffice-mco-user-enumeration-in-authentication  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-01. Updated: 2026-07-01  
License: CC BY 4.0 with a link back

CVE-2026-53908 · Severity: info · CVSS 6.9 · Published 2026-07-01

MyComplianceOffice (MCO) is a compliance management platform used by financial services and insurance firms to manage regulatory obligations. A security flaw in the system's login and password recovery features allows unauthorized individuals to determine which email addresses and usernames have active accounts. This information can be used to facilitate targeted phishing attacks or credential guessing against specific employees.

Technologies: [MyComplianceOffice MCO](https://junglewise.ai/threats/technologies/mco). Vendors: [MyComplianceOffice](https://junglewise.ai/threats/vendors/mycomplianceoffice).

## Quick answers

**Is CVE-2026-53908 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-53908 being exploited in the wild.

**How severe is CVE-2026-53908?** Informational severity, with a CVSS score of 6.9, published 1 July 2026.

**Which products and versions are affected?** MyComplianceOffice MCO 25.3.3.1.

**Is there a fix for CVE-2026-53908?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-53908 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-53908?** Check whether you run MyComplianceOffice MCO at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

MyComplianceOffice (MCO) version 25.3.3.1 is vulnerable to user enumeration (CWE-204) within its authentication-related endpoints. The application returns distinguishable responses for valid versus invalid users during username reminder and password reset operations. This discrepancy allows a remote, unauthenticated attacker to programmatically verify the existence of specific usernames or email addresses. While the vendor was contacted, they did not respond, and it is currently unknown if a patch is available. The vulnerability was assigned a CVSS 4.0 score of 6.9 by CERT.PL.

## Affected products

- MyComplianceOffice MCO 25.3.3.1

## Timeline

- 2026-07-01: disclosed: Vulnerability disclosed by CERT.PL after unsuccessful vendor contact attempts.
- 2026-07-01: advisory

## References

- [https://cert.pl/en/posts/2026/07/CVE-2026-53902](https://cert.pl/en/posts/2026/07/CVE-2026-53902)
- [https://mco.mycomplianceoffice.com/](https://mco.mycomplianceoffice.com/)

## Related threats

- [MyComplianceOffice MCO Unrestricted File Upload](https://junglewise.ai/threats/cve-2026-53909-mycomplianceoffice-mco-unrestricted-file-upload)
- [MyComplianceOffice MCO Stored XSS in logo upload](https://junglewise.ai/threats/cve-2026-53907-mycomplianceoffice-mco-stored-xss-in-logo-upload)
- [MyComplianceOffice MCO path traversal and path disclosure in file handling](https://junglewise.ai/threats/cve-2026-53906-mycomplianceoffice-mco-path-traversal-and-path-disclosure-in-file)
- [MyComplianceOffice MCO Incorrect Authorization in ACL Tree Endpoint](https://junglewise.ai/threats/cve-2026-53905-mycomplianceoffice-mco-incorrect-authorization-in-acl-tree)
- [MyComplianceOffice MCO Account Denial of Service in password reset](https://junglewise.ai/threats/cve-2026-53904-mycomplianceoffice-mco-account-denial-of-service-in-password)