What’s Vulnerable › Vulnerabilities
CVE-2026-53909: Arbitrary File Upload in MCO
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-07-01 · updated 2026-10-25
- Weakness: CWE-434
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.
Affected products
- Mycomplianceoffice: 25.3.3.1
References
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