Tilesheets MediaWiki Extension adds a table lookup parser function for an item and returns the requested image. A missing backtick in a query executed by the Tilesheets extension allows users to insert and potentially execute malicious SQL code. This issue has not been fixed.
https://github.com/FTB-Gamepedia/Tilesheets/security/advisories/GHSA-hqfr-7cm9-4h87