Unrated severityNVD Advisory· Published Jul 1, 2026· Updated Jul 1, 2026
Arbitrary File Upload in MCO
CVE-2026-53909
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.
Patches
Vulnerability mechanics
References
2- cert.pl/en/posts/2026/07/CVE-2026-53902mitrethird-party-advisory
- mco.mycomplianceoffice.commitreproduct
News mentions
0No linked articles in our index yet.