{"id":"GHSA-hc5v-gxvj-58wh","summary":"PraisonAI: MCP HTTP-stream transport is unauthenticated by default, exposing tool enumeration and an unvalidated tool-call surface","details":"## Summary\n\nPraisonAI's MCP HTTP-stream server authenticates requests only when an API key is configured; the CLI defaults `--api-key` to `None`, so `praisonai mcp serve --transport http-stream` exposes the full MCP surface unauthenticated. A request with no `Authorization` (and no `Origin`) can `initialize` and `tools/list` (~50 tools), and the dispatcher forwards tool-call arguments to handlers without validating them against the advertised `inputSchema`. Runtime-confirmed for unauthenticated `initialize`/`tools/list` and the dispatcher schema-bypass. This is **not** an RCE/file-read in 4.6.63 — `workflow.run`/`workflow.run_file` are runtime-refuted (adapter regression). Severity Medium–High.\n\n## Details\n\n### Affected component\n- Package: `praisonai` 4.6.63. Files: `src/praisonai/praisonai/mcp_server/transports/http_stream.py`, `mcp_server/cli.py`, `mcp_server/server.py` (dispatcher).\n\n### Vulnerable code / root cause\n\nPath:\n`src/praisonai/praisonai/mcp_server/transports/http_stream.py`\n\nFunction:\n`mcp_post` / `_validate_origin`\n\nSnippet:\n```python\nif self.api_key:                       # auth applied ONLY when api_key is set\n    auth_header = request.headers.get(\"Authorization\", \"\")\n    if not auth_header.startswith(\"Bearer \") or auth_header[7:] != self.api_key:\n        return JSONResponse({\"error\": \"Unauthorized\"}, status_code=401)\n# _validate_origin: returns True when the Origin header is absent\n```\nIssue: with `api_key=None`, no auth check runs; a missing `Origin` header is allowed, so non-browser clients (curl/Burp) are not blocked.\n\nPath:\n`src/praisonai/praisonai/mcp_server/cli.py`\n\nFunction:\n`cmd_serve` (argparse)\n\nSnippet:\n```python\nparser.add_argument(\"--api-key\", default=None)   # unauthenticated by default\n```\n\nPath:\n`src/praisonai/praisonai/mcp_server/server.py`\n\nFunction:\n`_handle_tools_call`\n\nSnippet:\n```python\nresult = await tool.handler(**arguments)   # arguments forwarded without inputSchema validation\n```\nIssue: attacker-controlled `arguments` are passed straight to the handler; the dispatcher does not validate them against the tool's advertised `inputSchema`. The only thing rejecting undeclared keys is the handler's own Python signature.\n\n### Attack flow\n1. Operator runs `praisonai mcp serve --transport http-stream` (no `--api-key`).\n2. Attacker (no auth, no Origin) sends `initialize` → session; `tools/list` → enumerates ~50 tools; `tools/call` → arguments pass through unvalidated.\n\n### Why existing protection is bypassed\nAuth is opt-in (only added when an api key is set); missing `Origin` is allowed; the dispatcher does not enforce `inputSchema`.\n\n### Security boundary\nUnauthenticated access to the MCP tool surface. Default bind `127.0.0.1` (any local process / multi-user host; remote only if `--host 0.0.0.0`).\n\n### Scope limits (do not overclaim)\n- `praisonai.workflow.run` / `workflow.run_file` are **runtime-refuted in 4.6.63**: the adapter calls `AgentsGenerator(...)` missing the required `config_list` argument → errors before any execution/file open. Several other tool adapters also error at runtime. No unauthenticated RCE/arbitrary-file-open via these tools at HEAD.\n- MCP `knowledge.add` file read is broken (see `FT-01_Knowledge_FileRead_Negative_Report.md`).\n\n## Proof of Concept\n\n### Environment\nReal MCP HTTP-stream server (`api_key=None`) in a local runtime (`127.0.0.1:18090`). Runnable assets: `PraisonAI-Runtime-Repro\\runtime-files\\` (`docker-compose.mcp.yml`). MCP requests use `Accept: application/json` + header `Mcp-Session-Id`.\n\n### Steps to reproduce\n1. `MCP-Initialize`: `POST /mcp` initialize (no Authorization) → `200` + `mcp-session-id`.\n2. `MCP-Tools-List-NoAuth`: `POST /mcp` `tools/list` with that session id → `200` + ~50 tools.\n3. `MCP-Schema-Bypass`: `tools/call` with an undeclared extra argument (`__undeclared_evil_param__`).\n\n### Expected result\nThe transport requires authentication; the dispatcher validates arguments against `inputSchema`.\n\n### Actual result\n- `initialize`/`tools/list` succeed with no auth and no Origin header.\n- The undeclared argument reaches the handler (`got an unexpected keyword argument '__undeclared_evil_param__'`), proving no schema validation at the dispatcher.\n\n### Screenshots\n\u003cimg width=\"1544\" height=\"798\" alt=\"03-MCP-Schema-Bypass\" src=\"https://github.com/user-attachments/assets/5a4cb764-9428-487d-b4e0-2854cbda7fb7\" /\u003e\n\u003cimg width=\"1538\" height=\"793\" alt=\"02-MCP-Tools-List-NoAuth\" src=\"https://github.com/user-attachments/assets/6356af71-867f-4fbc-a994-c7ca338fd2aa\" /\u003e\n\n### Screenshots\n\n**Unauthenticated MCP initialize**\n\nA POST request to `/mcp` with method `initialize` succeeds without an `Authorization` header. The server returns HTTP 200 OK, exposes MCP capabilities, and issues an `mcp-session-id` to the unauthenticated client.\n\n\u003cimg width=\"1546\" height=\"804\" alt=\"01-MCP-Initialize-NoAuth\" src=\"https://github.com/user-attachments/assets/2a62ee6b-99d3-4a38-a752-bfe6165c8c04\" /\u003e\n\n**Unauthenticated MCP tools/list**\n\nAfter initialization, the same unauthenticated MCP session can call `tools/list` using only the issued `Mcp-Session-Id`. The server returns HTTP 200 OK and exposes tool names, schemas, and annotations.\n\n\u003cimg width=\"1538\" height=\"793\" alt=\"02-MCP-Tools-List-NoAuth\" src=\"https://github.com/user-attachments/assets/f55189ff-13aa-4c36-a617-3d2ee4a52a84\" /\u003e\n\n**MCP tool-call schema bypass**\n\nThe unauthenticated MCP client calls `tools/call` with an extra argument not declared in the tool schema. Instead of rejecting the schema-violating input at the dispatcher layer, the unexpected parameter reaches the Python handler and causes an `unexpected keyword argument` error. This confirms incomplete input-schema enforcement for tool calls.\n\n\u003cimg width=\"1544\" height=\"798\" alt=\"03-MCP-Schema-Bypass\" src=\"https://github.com/user-attachments/assets/d3f36e50-2363-4eb2-8b3c-985ff0e27f6e\" /\u003e\n\n## Impact\nUnauthenticated tool enumeration and tool-call surface; LLM-key/cost abuse and data access via whichever tools function (impact currently limited by several broken adapters and the default loopback bind). No confirmed unauthenticated RCE/file-read in 4.6.63.","aliases":["CVE-2026-61427"],"modified":"2026-10-08T22:15:05.491500456Z","published":"2026-10-08T21:58:42Z","database_specific":{"cwe_ids":["CWE-20","CWE-306","CWE-862"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-10-08T21:58:42Z","nvd_published_at":"2026-07-15T17:16:52Z"},"references":[{"type":"WEB","url":"https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-hc5v-gxvj-58wh"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61427"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-62178"},{"type":"PACKAGE","url":"https://github.com/MervinPraison/PraisonAI"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/praisonai-before-authentication-bypass-via-http-stream"}],"affected":[{"package":{"name":"praisonai","ecosystem":"PyPI","purl":"pkg:pypi/praisonai"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.6.78"}]}],"versions":["0.0.1","0.0.10","0.0.11","0.0.12","0.0.13","0.0.14","0.0.15","0.0.16","0.0.17","0.0.18","0.0.19","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","0.0.52","0.0.53","0.0.54","0.0.55","0.0.56","0.0.57","0.0.58","0.0.59","0.0.59rc11","0.0.59rc2","0.0.59rc3","0.0.59rc5","0.0.59rc6","0.0.59rc7","0.0.59rc8","0.0.59rc9","0.0.6","0.0.61","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","0.0.8","0.0.9","0.1.0","0.1.1","0.1.10","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","1.0.0","1.0.1","1.0.10","1.0.11","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.0.8","1.0.9","2.0.0","2.0.1","2.0.10","2.0.11","2.0.12","2.0.13","2.0.14","2.0.15","2.0.16","2.0.17","2.0.18","2.0.19","2.0.2","2.0.20","2.0.22","2.0.23","2.0.24","2.0.25","2.0.26","2.0.27","2.0.28","2.0.29","2.0.3","2.0.30","2.0.31","2.0.32","2.0.33","2.0.34","2.0.35","2.0.36","2.0.37","2.0.38","2.0.39","2.0.40","2.0.41","2.0.42","2.0.43","2.0.44","2.0.45","2.0.46","2.0.47","2.0.48","2.0.49","2.0.5","2.0.50","2.0.51","2.0.53","2.0.54","2.0.55","2.0.56","2.0.57","2.0.58","2.0.59","2.0.6","2.0.60","2.0.61","2.0.62","2.0.63","2.0.64","2.0.65","2.0.66","2.0.67","2.0.68","2.0.69","2.0.7","2.0.70","2.0.71","2.0.72","2.0.73","2.0.74","2.0.75","2.0.76","2.0.77","2.0.78","2.0.79","2.0.8","2.0.80","2.0.81","2.0.9","2.1.0","2.1.1","2.1.4","2.1.5","2.1.6","2.2.1","2.2.10","2.2.11","2.2.12","2.2.13","2.2.14","2.2.15","2.2.16","2.2.17","2.2.18","2.2.19","2.2.2","2.2.20","2.2.21","2.2.22","2.2.24","2.2.25","2.2.26","2.2.27","2.2.28","2.2.29","2.2.3","2.2.30","2.2.31","2.2.32","2.2.33","2.2.34","2.2.35","2.2.36","2.2.37","2.2.38","2.2.39","2.2.4","2.2.40","2.2.41","2.2.42","2.2.43","2.2.44","2.2.45","2.2.46","2.2.47","2.2.48","2.2.49","2.2.5","2.2.50","2.2.51","2.2.52","2.2.53","2.2.54","2.2.55","2.2.56","2.2.57","2.2.58","2.2.59","2.2.6","2.2.60","2.2.61","2.2.62","2.2.63","2.2.64","2.2.65","2.2.66","2.2.67","2.2.68","2.2.69","2.2.7","2.2.70","2.2.71","2.2.72","2.2.73","2.2.74","2.2.75","2.2.76","2.2.77","2.2.78","2.2.79","2.2.8","2.2.80","2.2.81","2.2.82","2.2.83","2.2.84","2.2.86","2.2.87","2.2.88","2.2.89","2.2.9","2.2.90","2.2.91","2.2.93","2.2.95","2.2.96","2.2.97","2.2.98","2.2.99","2.3.0","2.3.1","2.3.10","2.3.11","2.3.12","2.3.13","2.3.14","2.3.15","2.3.16","2.3.18","2.3.19","2.3.2","2.3.20","2.3.21","2.3.22","2.3.23","2.3.24","2.3.25","2.3.26","2.3.27","2.3.28","2.3.29","2.3.3","2.3.30","2.3.31","2.3.32","2.3.33","2.3.34","2.3.35","2.3.36","2.3.37","2.3.38","2.3.39","2.3.4","2.3.40","2.3.41","2.3.42","2.3.43","2.3.44","2.3.45","2.3.46","2.3.47","2.3.48","2.3.49","2.3.5","2.3.50","2.3.51","2.3.52","2.3.53","2.3.54","2.3.55","2.3.56","2.3.57","2.3.58","2.3.59","2.3.6","2.3.60","2.3.61","2.3.62","2.3.63","2.3.64","2.3.65","2.3.66","2.3.67","2.3.68","2.3.69","2.3.7","2.3.70","2.3.71","2.3.72","2.3.73","2.3.74","2.3.75","2.3.76","2.3.77","2.3.78","2.3.79","2.3.8","2.3.80","2.3.81","2.3.82","2.3.83","2.3.84","2.3.85","2.3.86","2.3.87","2.3.9","2.4.0","2.4.1","2.4.2","2.4.3","2.4.4","2.5.0","2.5.1","2.5.2","2.5.3","2.5.4","2.5.5","2.5.6","2.5.7","2.6.0","2.6.1","2.6.2","2.6.3","2.6.4","2.6.5","2.6.6","2.6.7","2.6.8","2.7.0","2.8.3","2.8.4","2.8.5","2.8.6","2.8.7","2.8.8","2.8.9","2.9.0","2.9.1","2.9.2","3.0.0","3.0.1","3.0.2","3.0.3","3.0.4","3.0.5","3.0.6","3.0.7","3.0.8","3.0.9","3.1.0","3.1.1","3.1.2","3.1.3","3.1.4","3.1.5","3.1.6","3.1.7","3.1.8","3.1.9","3.10.0","3.10.1","3.10.10","3.10.11","3.10.12","3.10.13","3.10.14","3.10.15","3.10.16","3.10.17","3.10.18","3.10.19","3.10.2","3.10.20","3.10.21","3.10.22","3.10.23","3.10.24","3.10.25","3.10.26","3.10.27","3.10.3","3.10.4","3.10.5","3.10.6","3.10.7","3.10.8","3.10.9","3.11.0","3.11.1","3.11.10","3.11.11","3.11.12","3.11.13","3.11.14","3.11.2","3.11.3","3.11.4","3.1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4.6.77","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-hc5v-gxvj-58wh/GHSA-hc5v-gxvj-58wh.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"}]}