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CVE-2026-34935 — PraisonAI: OS Command Injection in praisonai —...

CRITICAL

PraisonAI: OS Command Injection in MCPHandler.parse_mcp_command()

Published April 1, 2026Updated June 29, 2026Source: osv

Summary

### Summary The `--mcp` CLI argument is passed directly to `shlex.split()` and forwarded through the call chain to `anyio.open_process()` with no validation, allowlist check, or sanitization at any hop, allowing arbitrary OS command execution as the process user. ### Details `cli/features/mcp.py:61` (source) -> `praisonaiagents/mcp/mcp.py:345` (hop) -> `mcp/client/stdio/__init__.py:253` (sink) ```python # source parts = shlex.split(command) # hop cmd, args, env = self.parse_mcp_command(command, env_vars) self.server_params = StdioServerParameters(command=cmd, args=arguments) # sink process = await anyio.open_process([command, *args]) ``` Fixed in commit `47bff65413beaa3c21bf633c1fae4e684348368c` (v4.5.69) by introducing a command allowlist: ```python ALLOWED_COMMANDS = {"npx", "uvx", "node", "python"} if cmd not in ALLOWED_COMMANDS: raise ValueError(f"Disallowed command: {cmd}") ``` ### PoC ```python # tested on: praisonai==4.5.48 # install: pip install praisonai==4.5.48 # run: praisonai --mcp "bash -c 'id > /tmp/pwned'" # verify: cat /tmp/pwned # expected output: uid=1000(...) gid=1000(...) groups=1000(...) ``` ### Impact Any deployment where the `--mcp` argument is influenced by untrusted input is exposed to full OS command execution as the process user. No authentication is required.

Advisory Timeline

  • First published April 1, 2026 (193 days ago).
  • Last revised June 29, 2026 — 89 days after initial publication.

Remediation

Upgrade to the fixed version using your package manager.

pip
Update praisonai to 4.5.69 or later
pip install "praisonai>=4.5.69"

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (1)

Affects 1 ecosystem: pypi (1).

PackageEcosystemAffectedFixed In
praisonai
pypi
4.5.15, 4.5.16, 4.5.18, 4.5.19 (+44 more)4.5.69

Vulnerability Classification

Common Weakness Enumeration (CWE) identifiers for this vulnerability type.

  • CWE-78
    OS Command InjectionMITRE

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 9.8 score means for each attack dimension.

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Frequently Asked Questions

What is CVE-2026-34935?
PraisonAI: OS Command Injection in MCPHandler.parse_mcp_command() This vulnerability has been assigned a severity rating of CRITICAL (CVSS score: 9.8/10).
How do I check if my project is affected by CVE-2026-34935?
CVE-2026-34935 affects praisonai. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2026-34935 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score
9.8

Exploitation is straightforward and causes maximum impact. Patch immediately.

Also Known As

GHSA-9gm9-c8mq-vq7m
PYSEC-2026-471

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