CVE-2026-34938 PraisonAI: Python Sandbox Escape via str Subclass startswith() Override in execute_code
Attackers can bypass the Python sandbox in PraisonAI to execute arbitrary OS commands on the host by exploiting a flaw in the execute_code function.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-34938?
CVE-2026-34938 is a critical code injection vulnerability in MervinPraison PraisonAI, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
PraisonAI is a multi-agent teams system. Prior to version 1.5.90, execute_code() in praisonai-agents runs attacker-controlled Python inside a three-layer sandbox that can be fully bypassed by passing a str subclass with an overridden startswith() method to the _safe_getattr wrapper, achieving arbitrary OS command execution on the host. This issue has been patched in version 1.5.90.
Weakness: CWE-693
Which versions are affected by CVE-2026-34938?
3 open source packages ship an affected version, including praisonaiagents. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
praisonaiagents PyPI | All versions | 1.5.90 |
praisonaiagents PyPI | All versions | 1.5.90 |
praisonaiagents PyPI | All versions | 1.5.90 |
Products include Praison Praisonaiagents.
How do I fix CVE-2026-34938?
Upgrade praisonaiagents to 1.5.90 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-34938 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34938 exists.
Other vulnerabilities in MervinPraison PraisonAI
- CVE-2026-40111 PraisonAIAgents has an OS Command Injection via shell=True in Memory Hooks Executor (memory/hooks.py)
- CVE-2026-34954 PraisonAI: SSRF in FileTools.download_file() via Unvalidated URL
- CVE-2026-34937 PraisonAI: Shell Injection in run_python() via Unescaped $() Substitution
- CVE-2026-44335 SSRF bypass in PraisonAI
- CVE-2026-40150 PraisonAIAgents has SSRF and Local File Read via Unvalidated URLs in web_crawl Tool
Sources
Also known as GHSA-6vh2-h83c-9294, PYSEC-2026-484.