# CVE-2026-39888

## Summary

- **CVE ID:** CVE-2026-39888
- **Severity:** CRITICAL
- **CVSS Score:** 10 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)
- **CWE:** CWE-657, CWE-693
- **Published:** Apr 8, 2026
- **Last Modified:** Apr 10, 2026

## Description

PraisonAI is a multi-agent teams system. Prior to 1.5.115, execute_code() in praisonaiagents.tools.python_tools defaults to sandbox_mode="sandbox", which runs user code in a subprocess wrapped with a restricted __builtins__ dict and an AST-based blocklist. The AST blocklist embedded inside the subprocess wrapper (blocked_attrs of python_tools.py) contains only 11 attribute names — a strict subset of the 30+ names blocked in the direct-execution path. The four attributes that form a frame-traversal chain out of the sandbox are all absent from the subprocess list (__traceback__, tb_frame, f_back, and f_builtins). Chaining these attributes through a caught exception exposes the real Python builtins dict of the subprocess wrapper frame, from which exec can be retrieved and called under a non-blocked variable name — bypassing every remaining security layer. This vulnerability is fixed in 1.5.115.

## Affected Products

- MervinPraison — praisonaiagents (< 1.5.115)

## References

- [CNA](https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-qf73-2hrx-xprp)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.48%
- **EPSS Percentile:** 39.6

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._