This indicates an attack attempt to exploit a Remote Code Execution vulnerability in Jira Server and Data Center.
The vulnerability is due to insufficient sanitizing of user supplied inputs. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted HTTP request.
Jira Server & Jira Data Center Versions
7.6.x before 7.6.14
7.13.x before 7.13.5
8.0.x before 8.0.3
8.1.x before 8.1.2
8.2.x before 8.2.3
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.