CVE-2026-57124: PraisonAI: Missing Authentication for Critical Function and Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in praisonai

The PraisonAI UI host apps (praisonai ui, praisonai ui agents, praisonai claw, and anything built on create_host_app() or build_host_app()) serve the PraisonAIUI Starlette app from aiui==0.3.121. Its api_mcp_connect handler reads JSON with a command and args, then connect_mcp_server builds a StdioMCPClient that launches that process. Authentication is opt-in: AuthEnforcementMiddleware only enforces it when AUTH_ENFORCE=true, and create_app defaults to require_auth=False.

A single request such as {"name":"evil","command":"/usr/bin/touch","args":["/tmp/pwned-by-ui-mcp"]} is enough. The researcher's proof of concept created the marker file even though the MCP handshake failed with a version mismatch between aiui and mcp. The process had already started, and the PoC retries to win the race.

Anyone who can reach the UI port gets code execution as the service user. Swap the touch for a shell and they can steal API keys and provider secrets in the environment, change files, or leave a long-running process. Teams that expose praisonai ui on a LAN, cloud host or container with a published port are the ones at risk.

The praisonai pip package at 4.6.48 and earlier. Version 4.6.48 (tag v4.6.48, commit d5f1114) was confirmed. The reporter says earlier releases that expose the same UI app are likely affected, and tested only the latest at the time. You are exposed when you run the UI commands or a host app with the ui or claw extras installed and the port is reachable. Check:

pip show praisonai aiui

Upgrade to praisonai 4.6.59 or later.

pip install --upgrade "praisonai>=4.6.59"

The advisory does not describe the code change. The reporter's recommendations were to remove caller-supplied command and args from the HTTP API, require auth on /api/mcp/connect, /api/mcp/disconnect/* and /api/mcp/servers, and bind to 127.0.0.1. Check the 4.6.59 release notes to see which were applied. Until you upgrade, bind the UI to localhost with --host 127.0.0.1 or put it behind a firewall or VPN. Setting AUTH_ENFORCE=true is a plausible mitigation but the advisory does not confirm it blocks this route, so test it.

Look in the web server or access logs for POST /api/mcp/connect from addresses you don't control. The UI logs lines such as Failed to connect to MCP stdio server even when the process has started. Check the process tree under the PraisonAI UI for unexpected children, and for new files such as /tmp/pwned-by-ui-mcp or the PoC's /tmp/praisonai_host_app_mcp_touch_marker.txt. Check GET /api/mcp/servers for entries you did not add. Treat any API keys in that process's environment as exposed if you find a hit.

Unauthenticated PraisonAI UI MCP connect endpoint executes attacker-chosen local commands

Summary

PraisonAI v4.6.48 exposes the PraisonAIUI MCP client management API through the default UI host apps without authentication. A remote unauthenticated client can send POST /api/mcp/connect with a command and args field. The endpoint passes those values into the MCP stdio client, which starts the attacker-selected local process as the PraisonAI UI service user.

The issue is reachable through PraisonAI's hosted UI integration (praisonai ui, praisonai ui agents, praisonai claw, and any app using praisonai.integration.host_app.create_host_app() / build_host_app()). praisonai ui and related Typer UI commands bind to 0.0.0.0 by default.

Affected Versions

Confirmed affected:

• praisonai v4.6.48
• Commit tested: d5f1114aaf1a2e9f121a6e66b929149ca2201f1d
• Tag tested: v4.6.48
• Pinned UI dependency: aiui==0.3.121 from src/praisonai/uv.lock

Likely affected:

• Any PraisonAI release that exposes aiui / praisonaiui create_app() through the PraisonAI UI host apps without authentication and includes the mcp dependency. I only confirmed the latest release during this audit.

Severity

Reasoning:

• AV: the vulnerable endpoint is an HTTP API route.
• AC: a single POST request is sufficient.
• PR: default UI host apps do not require credentials unless opt-in auth is configured.
• UI: no victim interaction is needed after the server is running.
• S: code executes in the PraisonAI UI server process context.
• C/I/A: arbitrary local command execution permits secret exfiltration, file tampering, and service disruption.

Root Cause

PraisonAI depends on MCP by default and exposes PraisonAIUI via optional UI extras:

• src/praisonai/pyproject.toml:11 includes base dependencies.
• src/praisonai/pyproject.toml:19 includes mcp>=1.20.0.
• src/praisonai/pyproject.toml:25 defines the ui extra with aiui>=0.3.121,<0.4.
• src/praisonai/pyproject.toml:197 defines the claw extra with aiui[all]>=0.3.121,<0.4.

PraisonAI's UI commands bind externally by default and launch aiui run:

• src/praisonai/praisonai/cli/commands/ui.py:114 sets host="0.0.0.0" for praisonai ui.
• src/praisonai/praisonai/cli/commands/ui.py:163 passes that host to aiui run.
• src/praisonai/praisonai/cli/commands/ui.py:186, :204, and :222 also default subcommands to 0.0.0.0.
• src/praisonai/praisonai/cli/commands/claw.py:41 defines the full dashboard command.
• src/praisonai/praisonai/cli/commands/claw.py:93 launches aiui run with the selected host.

PraisonAI's default apps create the PraisonAIUI Starlette app without forcing authentication:

• src/praisonai/praisonai/ui_chat/default_app.py:18 calls configure_host(...).
• src/praisonai/praisonai/ui_chat/default_app.py:142 exports app = create_host_app().
• src/praisonai/praisonai/claw/default_app.py:63 calls configure_host(...).
• src/praisonai/praisonai/claw/default_app.py:128 exports app = create_host_app().
• src/praisonai/praisonai/integration/host_app.py:174 imports praisonaiui.server.create_app.
• src/praisonai/praisonai/integration/host_app.py:180 returns create_app().

In aiui==0.3.121, the exposed server registers the MCP routes and auth is opt-in:

• praisonaiui/server.py:1483 defines api_mcp_connect.
• praisonaiui/server.py:1488 reads attacker-controlled JSON.
• praisonaiui/server.py:1491 accepts either command or url.
• praisonaiui/server.py:1496 calls connect_mcp_server(body).
• praisonaiui/server.py:2516 defines create_app(..., require_auth=False, ...).
• praisonaiui/server.py:2550 adds AuthEnforcementMiddleware, but it only enforces auth when AUTH_ENFORCE=true.
• praisonaiui/server.py:2769 registers /api/mcp/servers.
• praisonaiui/server.py:2770 registers /api/mcp/connect.

The MCP feature converts the request body into a local process launch:

• praisonaiui/features/mcp.py:325 defines connect_server(self, server_config).
• praisonaiui/features/mcp.py:330 chooses stdio transport when command is present.
• praisonaiui/features/mcp.py:332 constructs StdioMCPClient(command=server_config["command"], args=server_config.get("args", [])).
• praisonaiui/features/mcp.py:360 calls client.connect(), which invokes the MCP stdio transport and starts the process.

Minimal PoC

PoC file: poc/praisonai-aiui-mcp-connect-rce.py

The PoC runs the PraisonAI host app in-process, sends the unauthenticated HTTP request, and asks the server to execute /usr/bin/touch /tmp/praisonai_host_app_mcp_touch_marker.txt. It does not contact an LLM provider and uses no credentials.

Observed output from the tested checkout with aiui==0.3.121 and mcp==1.25.0 available:

[19:19:55] server.py:229 WARNING No auth_token provided for Gateway server. Generated temporary token: gw_****650a. For production, set GATEWAY_AUTH_TOKEN.
[19:19:55] mcp.py:135 ERROR Failed to connect to MCP stdio server: 'tuple' object has no attribute 'initialize'
HTTP_STATUS= 200
RESPONSE= {"server":{"name":"poc-stdio-process-0","transport":"stdio","status":"error","tools":[],"last_error":"Connection failed"}}
SUCCESS_AT_ATTEMPT= 0
MARKER_EXISTS= True
MARKER_PATH= /tmp/praisonai_host_app_mcp_touch_marker.txt

The MCP handshake fails because aiui==0.3.121 is not compatible with the locked mcp==1.25.0 return shape, but the attacker-selected process is already started. Process startup can race the immediate teardown caused by this version mismatch, so the checked-in PoC retries the same unauthenticated request until /usr/bin/touch wins scheduling and creates the marker. The marker file proves local command execution despite the reported MCP connection error.

Exploit Scenario

An operator runs:

pip install "praisonai[ui]"
praisonai ui

Because praisonai ui binds to 0.0.0.0 by default and the generated app does not require authentication by default, any host that can reach the UI port can send:

POST /api/mcp/connect
Content-Type: application/json

{
  "name": "evil",
  "command": "/usr/bin/touch",
  "args": ["/tmp/pwned-by-ui-mcp"]
}

In a real attack, the command can be replaced with a shell, a credential exfiltration command, a file modification command, or a payload that starts a long-lived process as the PraisonAI UI server user.

Novelty / Non-Duplicate Analysis

Searched sources:

• OSV query for PyPI praisonai: 51 advisories returned.
• OSV query for PyPI aiui: 0 advisories returned.
• OSV query for PyPI praisonaiui: 0 advisories returned.
• GitHub Advisory Database search for exact /api/mcp/connect, api_mcp_connect, StdioMCPClient, connect_mcp_server, and praisonaiui.features.mcp.
• NVD API searches for PraisonAI StdioMCPClient, PraisonAI api_mcp_connect, PraisonAI /api/mcp/connect, PraisonAIUI /api/mcp/connect, and aiui StdioMCPClient: 0 results.
• GitHub issue/PR searches in MervinPraison/PraisonAI for exact endpoint/function/class terms. Only one unrelated PR was returned for /api/mcp/connect; no issue/PR matched api_mcp_connect, StdioMCPClient, connect_mcp_server, or praisonaiui.features.mcp.
• Broad web searches for exact endpoint, file, class, and function terms returned no matching public vulnerability report.

Why this is distinct from known PraisonAI advisories:

• Not the excluded praisonai serve agents --api-key /agents auth bypass. This report targets POST /api/mcp/connect in the PraisonAIUI host app.
• Not GHSA-9gm9-c8mq-vq7m / CVE-2026-34935 or GHSA-9qhq-v63v-fv3j / CVE-2026-41497. Those involve MCPHandler.parse_mcp_command() command parsing. This finding uses praisonaiui.server.api_mcp_connect -> praisonaiui.features.mcp.connect_mcp_server -> StdioMCPClient.
• Not GHSA-pj2r-f9mw-vrcq / CVE-2026-40159. That advisory concerns sensitive environment variables inherited by untrusted MCP subprocesses. This finding is unauthenticated network-triggered local process execution.
• Not GHSA-6rmh-7xcm-cpxj or GHSA-8444-4fhq-fxpq. Those concern unauthenticated legacy/generated agent servers. This is a distinct UI route and a distinct sink that starts arbitrary local processes.
• Not GHSA-9cr9-25q5-8prj, GHSA-9mqq-jqxf-grvw, or other MCP server file-read/path-traversal advisories. This path is the UI MCP client connector, not PraisonAI's MCP server tool dispatcher.

Recommended Fix

1. Remove arbitrary command/args from the remote HTTP API. MCP stdio servers should be configured only from trusted local configuration, not caller-supplied JSON.
2. Require authentication and authorization on /api/mcp/connect, /api/mcp/disconnect/*, and /api/mcp/servers regardless of AUTH_ENFORCE.
3. Change UI command defaults from 0.0.0.0 to 127.0.0.1, or require an explicit --unsafe-expose style flag when binding externally without auth.
4. If remote MCP registration is a required feature, allow only URL-based transports with SSRF protections, or maintain an administrator-configured allowlist of commands.
5. Add regression tests that unauthenticated requests to /api/mcp/connect cannot start a subprocess, including when AUTH_ENFORCE is unset.