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Description

PraisonAI is a multi-agent teams system. Prior to 4.5.128, PraisonAI's AST-based Python sandbox can be bypassed using type.__getattribute__ trampoline, allowing arbitrary code execution when running untrusted agent code. The _execute_code_direct function in praisonaiagents/tools/python_tools.py uses AST filtering to block dangerous Python attributes like __subclasses__, __globals__, and __bases__. However, the filter only checks ast.Attribute nodes, allowing a bypass. The sandbox relies on AST-based filtering of attribute access but fails to account for dynamic attribute resolution via built-in methods such as type.getattribute, resulting in incomplete enforcement of security restrictions. The string '__subclasses__' is an ast.Constant, not an ast.Attribute, so it is never checked against the blocked list. This vulnerability is fixed in 4.5.128.

PUBLISHED Reserved 2026-04-09 | Published 2026-04-10 | Updated 2026-04-10 | Assigner GitHub_M




HIGH: 8.6CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Problem types

CWE-94: Improper Control of Generation of Code ('Code Injection')

CWE-693: Protection Mechanism Failure

Product status

< 4.5.128
affected

References

github.com/...isonAI/security/advisories/GHSA-3c4r-6p77-xwr7

cve.org (CVE-2026-40158)

nvd.nist.gov (CVE-2026-40158)

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