ArcadeDB is a Multi-Model DBMS. Prior to 26.6.1, the fix for CVE-2026-44221 added an UPDATE_SCHEMA authorization check only to LocalDocumentType.createProperty, while the remaining public schema mutators in engine/src/main/java/com/arcadedb/schema/LocalDocumentType.java and engine/src/main/java/com/arcadedb/schema/LocalProperty.java remained unchecked. An authenticated identity, including a read-only API token without UPDATE_SCHEMA permission, can use DROP PROPERTY, ALTER TYPE, or ALTER PROPERTY through the database command/query HTTP endpoints to rename types, change inheritance, alter aliases or buckets, drop properties, and change property constraints. The issue does not directly disclose or write record data, but unauthorized schema mutation can corrupt the meaning of stored records and breach the documented permission model. This issue is fixed in version 26.6.1.