CVE-2026-34955 PraisonAI: Sandbox Escape via shell=True and Bypassable Blocklist in SubprocessSandbox
Attackers can escape the SubprocessSandbox and execute arbitrary commands by bypassing the blocklist using shell=True in PraisonAI.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-34955?
CVE-2026-34955 is a high-severity command injection vulnerability in MervinPraison PraisonAI, published on 3 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
PraisonAI is a multi-agent teams system. Prior to version 4.5.97, SubprocessSandbox in all modes (BASIC, STRICT, NETWORK_ISOLATED) calls subprocess.run() with shell=True and relies solely on string-pattern matching to block dangerous commands. The blocklist does not include sh or bash as standalone executables, allowing trivial sandbox escape in STRICT mode via sh -c '<command>'. This issue has been patched in version 4.5.97.
Weakness: CWE-78
Which versions are affected by CVE-2026-34955?
3 open source packages ship an affected version, including praisonai. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
praisonai PyPI | All versions | 4.5.97 |
praisonai PyPI | All versions | 4.5.97 |
praisonai PyPI | All versions | 4.5.97 |
Products include Praison Praisonai.
How do I fix CVE-2026-34955?
Upgrade praisonai to 4.5.97 or later.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-34955 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34955 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-r4f2-3m54-pp7q, PYSEC-2026-2921.