Executive brief
ArcadeDB is a multi-model database platform that includes MCP (Model Context Protocol) server functionality for remote tool execution. The set_server_setting tool allows modification of server configuration settings. A flaw in authorization logic allows any authenticated read-only user to invoke administrative server configuration changes, bypassing the intended role-based access controls. This could allow an attacker to tamper with server settings, disable functionality, or degrade performance through denial-of-service attacks.
Technical details
The vulnerability is an authorization bypass in SetServerSettingTool.execute() that checks only the global allowAdmin configuration flag and fails to validate the caller's role or permissions. The tool receives the authenticated ServerSecurityUser principal but never verifies whether that user is authorized for server-level administration. In MCP deployments configured with allowAdmin=true and a permissive allowedUsers list, any authenticated read-only user can invoke set_server_setting to modify server GlobalConfiguration properties directly. The attack requires network access to the MCP endpoint and prior authentication as a read-only user. An attacker can modify runtime-mutable settings affecting timeouts, limits, metrics, and security reload intervals, enabling configuration tampering or denial-of-service. The issue is fixed in version 26.8.1.
Affected products
- ArcadeData ArcadeDB 26.4.2 through 26.7.3
Timeline
- 2026-08-04: disclosed
- 2026-08-18: advisory
- 2026-08-18: patched: fixed in version 26.8.1