Cross Site Request Forgery (CSRF) in the bolt/upload File Upload feature in Bolt CMS 3.6.6 allows remote attackers to execute arbitrary code by uploading a JavaScript file to include executable extensions in the file/edit/config/config.yml configuration file.
https://www.exploit-db.com/exploits/46664/
https://github.com/bolt/bolt/pull/7768/commits/91187aef36363a870d60b0a3c1bf8507af34c9e4