Path traversal in Code Graph RAG MCP lets attackers read files

Code Graph RAG is an AI-powered knowledge graph and retrieval system for querying, understanding, and editing multi-language codebases. Prior to 0.0.345, the MCPToolsRegistry.read_file implementation in codebase_rag/mcp/tools.py joins attacker-controlled file_path input to project_root without resolving and verifying containment when offset or limit selects the paginated branch. An absolute path causes pathlib to discard the configured root, while relative traversal can also resolve outside it. The protected non-paginated branch uses validate_project_path, but the paginated branch bypasses that validation before opening the path. An unauthenticated caller of a network-exposed HTTP MCP server can therefore read arbitrary UTF-8-readable files available to the server process, including credentials, environment data, private keys, source, and configuration; local callers through the stdio transport can reach the same vulnerable code path. This issue is fixed in version 0.0.345.