Provide references for CVE-2021-39609.
Where can I find more information about CVE-2021-39609?
References are available at: https://github.com/flatCore/flatCore-CMS/issues/53, https://github.com/nu11secur1ty/CVE-mitre/tree/main/CVE-2021-39609, https://www.nu11secur1ty.com/2021/08/cve-2021-39609.html.