Description
Joomla! Core is prone to multiple cross-site request forgery vulnerabilities. Exploiting these issues may allow a remote attacker to perform certain administrative actions and gain unauthorized access to the affected application; other attacks are also possible. Joomla! Core versions 3.x.x ranging from 3.0.0 and up to and including 3.9.14 are vulnerable.
Remediation
Update to Joomla! Core version 3.9.15 or latest
References
https://developer.joomla.org/security-centre/798-20200101-core-csrf-in-batch-actions.html
https://developer.joomla.org/security-centre/799-20200102-core-csrf-com-templates-less-compiler.html