Authenticated users and API tokens scoped to a specific database could read, write, and mutate schema on any other database on the same server. Two distinct defects contributed: (1) ServerSecurityUser.getDatabaseUser() returned a DB user with an uninitialized fileAccessMap, which requestAccessOnFile treated as allow-all; (2) ArcadeDBServer.createDatabase() omitted factory.setSecurity(...) so any database created via POST /api/v1/server {"command":"create database X"} had its entire record-level authorization system silently disabled. In combination, record-level and database-level authorization could be bypassed by any authenticated principal.
Upgrade to version 26.4.2
https://github.com/ArcadeData/arcadedb/commit/04110c06315da55604ac107f71fe7182f3a3deb8
26.4.2Exploitability
AV:NAC:LPR:LUI:RScope
S:CImpact
C:HI:HA:H9.0/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H