CVE-2021-27909
For Mautic versions prior to 3.3.4/4.0.0, there is an XSS vulnerability on Mautic’s password reset page where a vulnerable parameter, "bundle," in the URL could allow an attacker to execute Javascript code. The attacker would be required to convince or trick the target into clicking a password reset URL with the vulnerable parameter utilized.
Source: CVE-2021-27909