PraisonAI is a multi-agent teams system. From praisonaiagents 0.6.0 until 1.6.59 and PraisonAI 3.10.0 until 4.6.59, ToolsMCPServer.run_sse() in src/praisonai-agents/praisonaiagents/mcp/mcp_server.py mounts SseServerTransport on the legacy /sse and /messages/ endpoints without default Host, Origin, or authentication enforcement. A malicious website can use DNS rebinding against a reachable local or internal SSE server, supply attacker-controlled Host and Origin headers, enumerate registered tools, and invoke them with the server user's privileges. The Streamable HTTP transport rejects the same hostile Origin, which isolates the flaw to the legacy SSE wrapper. An initial remediation was released in praisonaiagents 1.6.59 and PraisonAI 4.6.59.

PraisonAI ToolsMCPServer legacy SSE transport accepts attacker Host/Origin and exposes registered tools