CVE-2026-53909

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.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://cert.pl/en/posts/2026/07/CVE-2026-53902	Third Party Advisory
https://mco.mycomplianceoffice.com/	Product

Configurations

Configuration 1 (hide)

cpe:2.3:a:mycomplianceoffice:mycomplianceoffice:25.3.3.1:*:*:*:*:*:*:*

History

06 Jul 2026, 13:47

Type	Values Removed	Values Added
CPE		cpe:2.3:a:mycomplianceoffice:mycomplianceoffice:25.3.3.1:::::::*
First Time		Mycomplianceoffice mycomplianceoffice Mycomplianceoffice
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 6.5
References	~~() https://cert.pl/en/posts/2026/07/CVE-2026-53902 -~~	() https://cert.pl/en/posts/2026/07/CVE-2026-53902 - Third Party Advisory
References	~~() https://mco.mycomplianceoffice.com/ -~~	() https://mco.mycomplianceoffice.com/ - Product

01 Jul 2026, 13:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-01 13:17

Updated : 2026-07-06 13:47

NVD link : CVE-2026-53909

Mitre link : CVE-2026-53909

CVE.ORG link : CVE-2026-53909

JSON object : View

Products Affected

mycomplianceoffice

mycomplianceoffice

CWE

CWE-434

Unrestricted Upload of File with Dangerous Type

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