CVE-2016-9836: Joomla!

Critical severity, CVSS 9.8. EPSS: 1.9% chance of exploitation in the next 30 days.

The file scanning mechanism of JFilterInput::isFileSafe() in Joomla! CMS before 3.6.5 does not consider alternative PHP file extensions when checking uploaded files for PHP content, which enables a user to upload and execute files with the `.php6`, `.php7`, `.phtml`, and `.phpt` extensions. Additionally, JHelperMedia::canUpload() did not blacklist these file extensions as uploadable file types.

Affected products

• Joomla! Joomla!: up to and including 3.6.4

Published 2016-12-05. Last modified 2026-06-17.