Joomla Extension - regularlabs.com - Unauthenticated RCE through unverified reflected user input in Sourcerer < 14.0.0 - Regular Labs Sourcerer before 14.0.0 processes {source} blocks found in Joomla’s final rendered HTML without reliably determining where that code originated.
Improper control of generation of code in the sourcerer extension for Joomla in versions before 11.0.0 lead to a remote code execution vulnerability.