Provide references for CVE-2021-3904.
Where can I find more information about CVE-2021-3904?
References are available at: https://huntr.dev/bounties/b1182515-d911-4da9-b4f7-b4c341a62a8d, https://github.com/getgrav/grav/commit/afc69a3229bb6fe120b2c1ea27bc6f196ed7284d.