CVE-2018-6383: Monstra

High severity, CVSS 8.8. EPSS: 13.5% chance of exploitation in the next 30 days.

Monstra CMS through 3.0.4 has an incomplete "forbidden types" list that excludes .php (and similar) file extensions but not the .pht or .phar extension, which allows remote authenticated Admins or Editors to execute arbitrary PHP code by uploading a file, a different vulnerability than CVE-2017-18048.

Affected products

• Monstra Monstra: up to and including 3.0.4

Published 2018-01-29. Last modified 2026-06-17.