CVE-2018-19420: Get-Simple Getsimple CMS

Low severity, CVSS 3.8. EPSS: 0.8% chance of exploitation in the next 30 days.

In GetSimpleCMS 3.3.15, admin/upload.php blocks .html uploads but there are several alternative cases in which HTML can be executed, such as a file with no extension or an unrecognized extension (e.g., the test or test.asdf filename), because of admin/upload-uploadify.php, and validate_safe_file in admin/inc/security_functions.php.

Affected products

• Get-Simple Getsimple CMS: version 3.3.15 only

Published 2018-11-21. Last modified 2026-06-17.