ArcadeDB (com.arcadedb) versions 26.7.3 and earlier fail to enforce the UPDATE_SCHEMA permission check when a DEFINE FUNCTION statement targets an already-existing function library. A user with only database access can add or overwrite SQL or Cypher functions in an existing library and persist the change, enabling tampering with admin-defined function logic. The issue is fixed in 26.8.1. (JavaScript functions still trigger the UPDATE_SECURITY check and are not affected.)