This indicates an attack attempt to exploit a Cross-Site Scripting Vulnerability in OPF OpenProject.
The vulnerability is due to insufficient sanitizing of user supplied inputs in the application. A remote attacker may be able exploit this to execute arbitrary script code within the context of the target user's browser.
OPF OpenProject 10.0.1 and before
System Compromise: Remote attackers can execute arbitrary script code within the context of the target user's browser.
Apply the most recent upgrade or patch from the vendor.