Postgres MCP Pro 0.3.0 contains a restricted-mode bypass vulnerability where function-name validation is not applied to RangeFunction nodes in FROM clauses. Attackers can execute file-reading functions like pg_read_file through FROM-clause syntax to read arbitrary files despite restricted-mode protections.

Postgres MCP Pro version 0.3.0 contains a security vulnerability that allows attackers to bypass restricted-mode protections. The flaw exists because function-name validation is not applied to RangeFunction nodes in SQL FROM clauses. Attackers can exploit this by using FROM-clause syntax to invoke sensitive functions such as pg_read_file, enabling arbitrary file reads on the server. This bypass undermines the intended security boundaries of restricted mode. The vulnerability is tracked as CVE-2026-85620 and was identified in the safe_sql.py component of the project. It poses a significant risk to environments relying on Postgres MCP Pro's restricted mode for access control. A fix would require extending function-name validation to cover RangeFunction nodes in FROM clauses. The issue has been reported via GitHub and documented by VulnCheck.