CVE-2026-40158 PraisonAI has Improper Control of Generation of Code ('Code Injection') and Protection Mechanism Failure in praisonai
Attackers can bypass the Python sandbox to execute arbitrary code when running untrusted agent code in PraisonAI.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-40158?
CVE-2026-40158 is a high-severity code injection vulnerability in MervinPraison PraisonAI, published on 10 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2026-40158?
3 open source packages ship an affected version, including praisonai and PraisonAI. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
praisonai PyPI | All versions | 4.5.128 |
praisonai PyPI | All versions | 4.5.128 |
PraisonAI PyPI | All versions | 4.5.128 |
Products include Praison Praisonai.
How do I fix CVE-2026-40158?
Upgrade praisonai to 4.5.128 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-40158 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40158 exists.
Other vulnerabilities in MervinPraison PraisonAI
- CVE-2026-39888 PraisonAIAgents has a sandbox escape via exception frame traversal in `execute_code` (subprocess mode)
- CVE-2026-41497 Incomplete fix for CVE-2026-34935: Command Injection in MervinPraison/PraisonAI
- CVE-2026-40288 PraisonAI: Critical RCE via `type: job` workflow YAML
- CVE-2026-39890 PraisonAI Affected by Remote Code Execution via YAML Deserialization in Agent Definition Loading
- CVE-2026-34934 PraisonAI: Second-Order SQL Injection in `get_all_user_threads`
Sources
Also known as GHSA-3c4r-6p77-xwr7, PYSEC-2026-2898.