CVE-2026-53909 Details
Description
MCO does not correctly validate types of uploaded files. File upload validation functionality relies only on client-side checks, which can be bypassed. An authorized, low-privileged attacker can upload files with arbitrary types to the server. Because vendor contact attempts were unsuccessful, the vulnerability has only been confirmed in version 25.3.3.1 but may also affect other versions.
A vulnerability exists in MyComplianceOffice (MCO) version 25.3.3.1, allowing authorized, low-privileged users to upload files of any type to the server. This issue arises because the file upload validation relies solely on client-side checks, which can be easily bypassed. While this vulnerability has been confirmed in version 25.3.3.1, it may also affect other versions.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 1, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://cert.pl/en/posts/2026/07/CVE-2026-53902 | [email protected] | Third Party Advisory |
| https://mco.mycomplianceoffice.com/ | [email protected] | Product |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-434 | Unrestricted Upload of File with Dangerous Type | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| mycomplianceoffice mycomplianceoffice | 25.3.3.1 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 6, 2026 | Initial Analysis | [email protected] |
| Jul 1, 2026 | CVE Modified | CISA-ADP |
| Jul 1, 2026 | New CVE Received | [email protected] |