delete_user

THE RISK

Critical Risk

Why delete_user needs a policy

This tool permanently removes a user account from the Open WebUI system. The deletion cannot be reversed, making it a destructive action. Combined with admin-only access restrictions and the explicit warning, the severity is critical due to the permanent loss of user data, access rights, and associated resources.

From the tool's definition Tool name is 'delete_user' and description explicitly states 'Delete a user' and 'WARNING: Cannot be undone!' These terms indicate permanent, irreversible deletion.

Risk signalsAdmin/system-level operation

Documented attack patterns abuse exactly the kind of access delete_user gives an agent:

POLICY

How to control delete_user

PolicyLayer is an MCP gateway — it sits between your AI agents and Open WebUI MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for delete_user:

policy.json

{
  "version": "1",
  "default": "deny",
  "hide": [
    "delete_user"
  ]
}

delete_user disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.

Create a free account and register Open WebUI MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RESTRICT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Open WebUI MCP Server tools

Destructive delete_all_chats Delete all your chats. WARNING: Cannot be undone! Destructive delete_all_files Delete all files. ADMIN ONLY. WARNING: Cannot be undone! Destructive delete_all_memories Delete all your memories. WARNING: Cannot be undone! Destructive delete_channel Delete a channel and all its messages. Destructive delete_channel_message Delete a message from a channel. Destructive delete_chat Delete a chat. Destructive delete_file Delete a file. Destructive delete_folder Delete a folder.

All 82 Open WebUI MCP Server tools →

Destructive tools on other servers

Android Forensics ADB MCP Server create_full_backup 0xarchive web3_revoke_key Frida Game Hacking MCP clear_scan cPanel MCP Server clear_spam_box

Go deeper

Critical-risk tools in Open WebUI MCP Server → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Blast radius → How much damage one compromised or confused agent can do — and how to bound it.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about delete_user

What does the delete_user tool do? +

Delete a user. ADMIN ONLY. WARNING: Cannot be undone!. It is categorised as a Destructive tool in the Open WebUI MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.

How do I enforce a policy on delete_user? +

Register the Open WebUI MCP Server MCP server in PolicyLayer and add a rule for delete_user: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Open WebUI MCP Server. Nothing to install.

What risk level is delete_user? +

delete_user is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit delete_user? +

Yes. Add a rate_limit block to the delete_user rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block delete_user completely? +

Set action: deny in the PolicyLayer policy for delete_user. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides delete_user? +

delete_user is provided by the Open WebUI MCP Server MCP server (troylar/open-webui-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Open WebUI MCP Server tool call.

Start from Open WebUI MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →