CVE-2026-39888 PUBLISHED

PraisonAIAgents has a sandbox escape via exception frame traversal in `execute_code` (subprocess mode)

Assigner: GitHub_M
Reserved: 07.04.2026 Published: 08.04.2026 Updated: 08.04.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS Score: 10

Product Status

Vendor MervinPraison
Product praisonaiagents
Versions
  • Version < 1.5.115 is affected

References

Problem Types

  • CWE-657: Violation of Secure Design Principles CWE
  • CWE-693: Protection Mechanism Failure CWE