A flaw was found where some utility classes in Drools core did not use proper safeguards when deserializing data. This flaw allows an authenticated attacker to construct malicious serialized objects (usually called gadgets) and achieve code execution on the server.
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:N8.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:NSerialization