CVE-2026-47392 — PraisonAI vulnerable to sandbox escape via `print.self` builtins module leak in `execute_code` (subprocess mode)

Affected: MervinPraison PraisonAI, MervinPraison < 1.6.40

PraisonAI is a multi-agent teams system. Prior to version 4.6.40 of PraisonAI, corresponding to version 1.6.40 of praisonaiagents, `execute_code()` in `praisonaiagents/tools/python_tools.py` (v1.6.37, subprocess sandbox mode) can be fully bypassed using `print.__self__` to retrieve the real Python `builtins` module, from which `__import__` can be extracted via `vars()` and runtime string construction. This achieves arbitrary OS command execution on the host, completely defeating the sandbox. This is a novel bypass that survives all patches for CVE-2026-39888 (frame traversal), CVE-2026-34938 (str subclass), and CVE-2026-40158 (`type.__getattribute__` trampoline). PraisonAI version 4.6.40 and praisonaiagents version 1.6.40 contain an updated fix.

GHSA-4mr5-g6f9-cfrh — PraisonAI vulnerable to sandbox escape via `print.self` builtins module leak in `execute_code` (subprocess mode)

Affected: PyPI: praisonaiagents, PyPI: PraisonAI

## Summary

`execute_code()` in `praisonaiagents/tools/python_tools.py` (v1.6.37, subprocess sandbox mode) can be fully bypassed using `print.__self__` to retrieve the real Python `builtins` module, from which `__import__` can be extracted via `vars()` and runtime string construction. This achieves arbitrary OS command execution on the host, completely defeating the sandbox.

This is a **novel bypass** that survives all patches for CVE-2026-39888 (frame traversal), CVE-2026-34938 (str subclass), and CVE-2026-40158 (`type.__getattribute__` trampoline).

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## Severity

**CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H — 9.9 Critical**

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## Root Cause

Three independent gaps in the AST-based security validation:

### Gap 1: `__self__` missing from `_blocked_attrs`

In CPython, all built-in functions (C-level functions) have a `__self__` attribute that returns the module they belong to. The built-in functions in `safe_builtins` (`print`, `len`, `range`, etc.) are the *real* CPython built-in functions, so `print.__self__` returns `<module 'builtins' (built-in)>`.

The `_blocked_attrs` frozenset (line 52) does NOT include `__self__`. The AST check at line 74 only blocks attributes that are IN this set, so `print.__self__` passes.

### Gap 2: `vars` not blocked as callable or attribute

`builtins.vars(obj)` returns `obj.__dict__`. The function name `vars` is not in the AST `Call` blocklist (line 83: only blocks `exec`, `eval`, `compile`, `__import__`, `open`, `input`, `breakpoi…

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CVE-2026-47392 — PraisonAI vulnerable to sandbox escape via `print.__self__` builtins module leak in `execute_code` (subprocess mode)

GHSA-4mr5-g6f9-cfrh — PraisonAI vulnerable to sandbox escape via `print.__self__` builtins module leak in `execute_code` (subprocess mode)

CVE-2026-47392 — PraisonAI vulnerable to sandbox escape via `print.self` builtins module leak in `execute_code` (subprocess mode)

GHSA-4mr5-g6f9-cfrh — PraisonAI vulnerable to sandbox escape via `print.self` builtins module leak in `execute_code` (subprocess mode)