Executive brief
PraisonAI, a framework for managing AI agents, contains a security flaw where its Model Context Protocol (MCP) server is accessible without a password by default. If an operator runs the server on a public network address, an unauthorized user could connect to the system, view available AI tools, and trigger tool functions. This could lead to unauthorized data access or abuse of AI services and associated API costs.
Technical details
PraisonAI's MCP HTTP-stream transport (src/praisonai/praisonai/mcp_server/transports/http_stream.py) only enforces Authorization/Bearer checks if an API key is configured; however, the CLI --api-key option defaults to None. Consequently, an unauthenticated attacker can initialize a session and access the tools/list and tools/call endpoints. Furthermore, the dispatcher in mcp_server/server.py forwards tool-call arguments directly to handlers without validating them against the advertised inputSchema, allowing for the injection of undeclared parameters. While the server binds to 127.0.0.1 by default, remote exploitation is possible if the operator binds to a network-accessible address (e.g., via --host 0.0.0.0). The issue is resolved in version 4.6.78.
Affected products
- MervinPraison PraisonAI < 4.6.78
Timeline
- 2026-06-25: advisory: GitHub Security Advisory published
- 2026-07-15: disclosed: NVD publication date
- 2026-07-15: patched: Fix confirmed in version 4.6.78