What’s Vulnerable › Vulnerabilities
CVE-2026-39888: PraisonAIAgents has a sandbox escape via exception frame traversal in `execute_code` (subprocess mode)
- Severity: critical (CVSS 9.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-04-08 · updated 2026-07-24
- Weakness: CWE-657
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 PraisonAI: before 1.5.115 — fixed in 1.5.115
How to fix
Upgrade to a fixed version: MervinPraison PraisonAI 1.5.115. Check the vendor advisory for mitigations.
References
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