plone.restapi in Plone 5.2.0 through 5.2.1 allows users with a certain privilege level to escalate their privileges up to the highest level.
5.2.26.2.1Exploitability
AV:NAC:LAT:NPR:LUI:NVulnerable System
VC:HVI:HVA:HSubsequent System
SC:NSI:NSA:N8.7/CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N