{"id":"PYSEC-2026-3536","summary":"PraisonAI: MCP SSE transport binds 0.0.0.0 with no authentication and no Origin validation; bundled SecurityConfig is never wired in","details":"The MCP SSE server started via ToolsMCPServer.run_sse() / launch_tools_mcp_server(transport=\"sse\")\nbinds to 0.0.0.0 by default and builds its Starlette application with no authentication middleware\nand no Origin-header validation. The module mcp/mcp_security.py provides exactly the needed controls\n(origin validation, DNS-rebinding detection, auth-header enforcement, a SecurityConfig), but none of\nthese functions are ever called by any transport — they are dead code. Any host that can reach the\nport can list and invoke every registered tool with no credentials, and a victim's browser can drive\nthe same calls against a localhost instance via DNS rebinding.\n\nAffected code: src/praisonai-agents/praisonaiagents/mcp/mcp_server.py\n- run_sse defaults host to all interfaces (line 245) and builds the app with only `debug` and `routes`\n  - no `middleware=` and no per-route auth/origin gate (lines ~271-289):\n      app = Starlette(debug=self._debug, routes=[\n          Route(sse_path, endpoint=handle_sse),                          # \"/sse\"\n          Mount(messages_path, app=sse_transport.handle_post_message),   # \"/messages/\"\n      ])\n      uvicorn.run(app, host=host, port=port)\n- launch_tools_mcp_server also defaults host=\"0.0.0.0\" (line 301).\n\nsrc/praisonai-agents/praisonaiagents/mcp/mcp_security.py defines but the transports never call:\n- is_valid_origin (line 30), is_potential_dns_rebinding (line 110), validate_auth_header (line 167),\n  SecurityConfig.is_origin_allowed (line 236). These symbols are referenced only inside mcp_security.py\n  and the __init__ re-export. (mcp_websocket.py's auth references are CLIENT-side, not server validation.)\n\nImpact:\nlaunch_tools_mcp_server(transport=\"sse\") is the documented path for exposing tools over MCP. With the\ndefaults above it is an unauthenticated, network-reachable tool-execution endpoint. Blast radius equals\nthe capabilities of the registered tools; with file/shell/code-exec tools this is RCE. With no Origin\ncheck, a malicious page the victim merely visits can rebind its hostname to 127.0.0.1 and issue the\nJSON-RPC calls cross-origin against a developer's local server.\n\nProof of concept:\nStatic proof (AST analysis of unmodified source):\n  Check 1 - run_sse(host='0.0.0.0'); launch_tools_mcp_server(host='0.0.0.0')  -\u003e EXPOSED\n  Check 2 - Starlette(...) kwargs: ['debug','routes']  -\u003e NO middleware= (no auth/origin gate)\n  Check 3 - is_valid_origin / is_potential_dns_rebinding / validate_auth_header / SecurityConfig\n            never called by any transport  -\u003e DEAD CODE\nLive exploitation against a running server:\n  curl -N http://VICTIM:8080/sse\n  #   event: endpoint  / data: /messages/?session_id=\u003csid\u003e\n  curl -X POST \"http://VICTIM:8080/messages/?session_id=\u003csid\u003e\" -H 'Content-Type: application/json' \\\n    -d '{\"jsonrpc\":\"2.0\",\"id\":1,\"method\":\"initialize\",\"params\":{\"protocolVersion\":\"2024-11-05\",\n         \"capabilities\":{},\"clientInfo\":{\"name\":\"x\",\"version\":\"1\"}}}'\n  curl -X POST \"http://VICTIM:8080/messages/?session_id=\u003csid\u003e\" -H 'Content-Type: application/json' \\\n    -d '{\"jsonrpc\":\"2.0\",\"id\":2,\"method\":\"tools/call\",\"params\":{\"name\":\"\u003ctool\u003e\",\"arguments\":{...}}}'\nNo Authorization header anywhere. Browser DNS-rebinding variant drives the same calls cross-origin.\n\nRemediation:\nWire in the existing mcp_security.py controls and fix defaults:\n- Default run_sse(host=\"127.0.0.1\"); require explicit opt-in to bind 0.0.0.0.\n- Attach Starlette middleware calling is_valid_origin / is_potential_dns_rebinding; reject bad origins.\n- Enforce validate_auth_header when SecurityConfig.require_auth; default require_auth=True (and\n  allow_missing_origin=False) for any non-loopback bind.\n\nDistinct from prior advisories:\nThe accepted MCP advisories are tool-handler bugs — tools/call path traversal -\u003e .pth RCE\n(GHSA-9mqq-jqxf-grvw) and unauthenticated file read via workflow.show/validate (GHSA-9cr9-25q5-8prj).\nThis is a transport-layer missing-auth/exposure: the SSE server never enforces auth or Origin validation\nand ignores the security module the codebase ships. Closest in spirit to the default-insecure pattern\n(GHSA-8444 / 86qc) but a different server and a different root cause (unwired controls, not an unset env var).","aliases":["CVE-2026-57123","GHSA-x227-pf99-vffg"],"modified":"2026-07-23T15:00:23.782569014Z","published":"2026-07-23T11:41:41.167810Z","references":[{"type":"WEB","url":"https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-x227-pf99-vffg"},{"type":"PACKAGE","url":"https://github.com/MervinPraison/PraisonAI"},{"type":"PACKAGE","url":"https://pypi.org/project/praisonaiagents"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-x227-pf99-vffg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-57123"}],"affected":[{"package":{"name":"praisonaiagents","ecosystem":"PyPI","purl":"pkg:pypi/praisonaiagents"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.59"}]}],"versions":["0.0.1","0.0.10","0.0.100","0.0.101","0.0.102","0.0.103","0.0.104","0.0.105","0.0.106","0.0.107","0.0.108","0.0.109","0.0.11","0.0.110","0.0.111","0.0.112","0.0.113","0.0.114","0.0.115","0.0.116","0.0.117","0.0.118","0.0.119","0.0.12","0.0.120","0.0.121","0.0.122","0.0.123","0.0.124","0.0.125","0.0.126","0.0.127","0.0.128","0.0.129","0.0.13","0.0.130","0.0.131","0.0.132","0.0.133","0.0.134","0.0.135","0.0.136","0.0.137","0.0.138","0.0.139","0.0.14","0.0.140","0.0.141","0.0.142","0.0.143","0.0.144","0.0.145","0.0.146","0.0.147","0.0.148","0.0.149","0.0.15","0.0.150","0.0.151","0.0.152","0.0.153","0.0.154","0.0.155","0.0.156","0.0.157","0.0.158","0.0.159","0.0.16","0.0.160","0.0.161","0.0.162","0.0.163","0.0.164","0.0.165","0.0.166","0.0.167","0.0.168","0.0.169","0.0.17","0.0.170","0.0.171","0.0.172","0.0.173","0.0.174","0.0.175","0.0.176","0.0.177","0.0.178","0.0.179","0.0.18","0.0.180","0.0.181","0.0.182","0.0.183","0.0.184","0.0.185","0.0.187","0.0.188","0.0.189","0.0.19","0.0.190","0.0.191","0.0.192","0.0.193","0.0.194","0.0.195","0.0.196","0.0.197","0.0.198","0.0.199","0.0.2","0.0.20","0.0.21","0.0.22","0.0.23","0.0.24","0.0.25","0.0.26","0.0.27","0.0.28","0.0.29","0.0.3","0.0.30","0.0.31","0.0.32","0.0.33","0.0.34","0.0.35","0.0.36","0.0.37","0.0.38","0.0.39","0.0.4","0.0.40","0.0.41","0.0.42","0.0.43","0.0.44","0.0.45","0.0.46","0.0.47","0.0.48","0.0.49","0.0.5","0.0.50","0.0.51","0.0.52","0.0.53","0.0.54","0.0.56","0.0.57","0.0.58","0.0.59","0.0.6","0.0.60","0.0.61","0.0.62","0.0.63","0.0.64","0.0.65","0.0.66","0.0.67","0.0.68","0.0.69","0.0.7","0.0.70","0.0.71","0.0.72","0.0.73","0.0.74","0.0.75","0.0.76","0.0.77","0.0.78","0.0.79","0.0.8","0.0.80","0.0.81","0.0.82","0.0.83","0.0.84","0.0.85","0.0.86","0.0.87","0.0.88","0.0.89","0.0.9","0.0.90","0.0.91","0.0.92","0.0.93","0.0.94","0.0.95","0.0.96","0.0.97","0.0.98","0.0.99","0.1.0","0.1.1","0.1.10","0.1.11","0.1.12","0.1.13","0.1.14","0.1.15","0.1.16","0.1.17","0.1.18","0.1.19","0.1.2","0.1.20","0.1.21","0.1.22","0.1.23","0.1.24","0.1.25","0.1.26","0.1.27","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.10.0","0.10.1","0.10.10","0.10.2","0.10.3","0.10.4","0.10.5","0.10.6","0.10.7","0.10.8","0.10.9","0.11.0","0.11.1","0.11.10","0.11.11","0.11.12","0.11.13","0.11.14","0.11.15","0.11.16","0.11.17","0.11.18","0.11.19","0.11.2","0.11.20","0.11.21","0.11.22","0.11.23","0.11.24","0.11.25","0.11.27","0.11.28","0.11.29","0.11.3","0.11.30","0.11.31","0.11.4","0.11.5","0.11.6","0.11.7","0.11.8","0.11.9","0.12.0","0.12.1","0.12.10","0.12.11","0.12.12","0.12.13","0.12.14","0.12.15","0.12.16","0.12.17","0.12.18","0.12.19","0.12.2","0.12.20","0.12.21","0.12.3","0.12.4","0.12.5","0.12.6","0.12.7","0.12.8","0.12.9","0.13.0","0.13.1","0.13.10","0.13.11","0.13.12","0.13.13","0.13.14","0.13.15","0.13.16","0.13.17","0.13.18","0.13.19","0.13.2","0.13.20","0.13.21","0.13.22","0.13.23","0.13.3","0.13.4","0.13.5","0.13.6","0.13.7","0.13.8","0.13.9","0.14.0","0.14.1","0.14.10","0.14.11","0.14.12","0.14.14","0.14.15","0.14.16","0.14.2","0.14.3","0.14.4","0.14.5","0.14.6","0.14.7","0.14.8","0.14.9","0.15.0","0.15.1","0.15.2","0.15.3","0.2.0","0.2.1","0.2.2","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.4.0","0.4.1","0.5.0","0.5.1","0.5.2","0.5.3","0.6.0","0.6.1","0.6.2","0.6.3","0.6.4","0.6.5","0.6.6","0.6.7","0.6.8","0.7.0","0.7.1","0.8.0","0.8.1","0.9.0","0.9.1","1.0.0","1.1.0","1.2.0","1.2.1","1.2.2","1.2.3","1.2.4","1.3.0","1.3.1","1.4.0","1.4.1","1.4.2","1.4.3","1.4.4","1.4.5","1.4.6","1.4.7","1.4.8","1.5.0","1.5.1","1.5.10","1.5.100","1.5.101","1.5.102","1.5.103","1.5.104","1.5.105","1.5.106","1.5.107","1.5.108","1.5.109","1.5.11","1.5.110","1.5.111","1.5.112","1.5.113","1.5.114","1.5.115","1.5.116","1.5.117","1.5.118","1.5.119","1.5.12","1.5.120","1.5.121","1.5.122","1.5.123","1.5.124","1.5.125","1.5.126","1.5.127","1.5.128","1.5.129","1.5.13","1.5.130","1.5.131","1.5.132","1.5.133","1.5.134","1.5.135","1.5.136","1.5.137","1.5.138","1.5.139","1.5.14","1.5.140","1.5.141","1.5.142","1.5.143","1.5.144","1.5.145","1.5.146","1.5.147","1.5.148","1.5.149","1.5.15","1.5.16","1.5.17","1.5.18","1.5.19","1.5.2","1.5.20","1.5.21","1.5.22","1.5.23","1.5.24","1.5.25","1.5.26","1.5.27","1.5.28","1.5.29","1.5.3","1.5.30","1.5.31","1.5.32","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