CVE-2026-40158:
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.
Score
A numerical rating that indicates how dangerous this vulnerability is.
7.8High- Published Date:Apr 10, 2026
- CISA KEV Date:*No Data*
- Industries Affected:20
Threat Predictions
- EPSS Score:0.0
- EPSS Percentile:7%
Exploitability
- Score:1.8
- Attack Vector:LOCAL
- Attack Complexity:LOW
- Privileges Required:NONE
- User Interaction:REQUIRED
- Scope:UNCHANGED
Impact
- Score:5.9
- Confidentiality Impact:HIGH
- Integrity Impact:HIGH
- Availability Impact:HIGH
Description Preview
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.
Industries Affected
Below is a list of industries most commonly impacted or potentially at risk based on intelligence.
