Multiple reflected XSS were found on different JSP files with unsanitized parameters in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms that an attacker can modify to craft a malicious XSS payload. The solution is to upgrade to Meridian 2023.1.6, 2022.1.19, 2021.1.30, 2020.1.38 or Horizon 32.0.2 or newer. Meridian and Horizon installation instructions state that they are intended for installation within an organization's private networks and should not be directly accessible from the Internet. OpenNMS thanks Jordi Miralles Comins for reporting this issue.