ArcadeDB versions prior to 26.7.3 do not properly bind the authenticated principal in the MCP HTTP transport, causing all engine permission checks to become no‑ops. As a result, any user with MCP access—even non‑root users—can perform arbitrary writes, data‑definition statements, schema mutations, and run JavaScript code through the query tool. This vulnerability effectively allows an authenticated attacker to modify data, create malicious users, alter the database schema, and execute arbitrary code within the database environment, jeopardizing data integrity and confidentiality.

ArcadeData ArcadeDB deployments running any release before 26.7.3 are affected. The issue exists across all platform variants that expose the MCP HTTP transport and do not patch to the 26.7.3 version or later.

The CVSS score of 7.7 indicates a high severity. No EPSS score is available, and the vulnerability is not listed in the CISA KEV catalog. The MCP HTTP transport is normally exposed to remote clients; the likely attack vector is a remote attacker authenticating with a non‑root MCP‑allowed user. Because the system silently bypasses permission checks, the attacker can execute arbitrary commands and JavaScript, potentially leading to remote code execution or full database compromise. The lack of network restriction or privilege constraints increases the likelihood of exploitation, especially in environments where the MCP port is reachable from untrusted networks.