CVE-2026-44336: PraisonAI MCP `tools/call` path-traversal => RCE via Python `.pth` injection

PraisonAI’s MCP (Model Context Protocol) server (praisonai mcp serve) registers four file-handling tools by default — praisonai.rules.create, praisonai.rules.show, praisonai.rules.delete, and praisonai.workflow.show. Each accepts a path or filename string from MCP tools/call arguments and joins it onto ~/.praison/rules/ (or, for workflow.show, accepts an absolute path) with no containment check. The JSON-RPC dispatcher passes params["arguments"] blind to each handler via **kwargs without validating against the advertised input schema.

By setting rule_name="../../<some-path>" an attacker walks out of the rules directory and writes any file the running user can write. Dropping a Python .pth file into the user site-packages directory escalates this primitive to arbitrary code execution in any subsequent Python process the user spawns — the next praisonai CLI invocation, an IDE script run, the user’s python REPL, or any background Python service. The same primitive is reachable from:

• An MCP-connected LLM (Claude Desktop, Cursor, Continue.dev, Claude Code) whose context is poisoned by attacker-controlled web content / documents / emails — no operator click required beyond ordinary “ask the LLM to summarise this page” usage.
• praisonai mcp serve --transport http-stream with no --api-key (default), reachable from any local process / DNS-rebound browser tab / container neighbour sharing loopback.
• Stdio MCP from any prompt-injection vector that reaches the connected LLM.

No operator misconfiguration is required. No env var, flag, or config switch disables the vulnerable handlers.