browser_page_state

THE RISK

Low Risk

Why browser_page_state needs a policy

This tool retrieves data from the browser page including form data, storage values, and cookies — all read operations with no side effects. However, severity is medium because cookies and storage values may contain sensitive information like session tokens, authentication credentials, or personal data that could be exfiltrated if misused.

From the tool's definition Extract form data, storage values, and cookies from the active page

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

POLICY

How to control browser_page_state

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

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "browser_page_state": {}
  }
}

browser_page_state is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

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

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More YetiBrowser MCP tools

Execute browser_evaluate Run custom JavaScript inside the page context and return the JSON-serializable result. Execute browser_wait Wait for a specified time in seconds Execute browser_wait_for Wait until a selector appears (optionally visible) before continuing. Returns a fresh snap Execute browser_click Perform click on a web page Execute browser_drag Drag an element (like cards in a kanban board) onto a target element. Useful for sortable Execute browser_fill_form Fill multiple form fields in a single call. Supports inputs, textareas, selects, checkboxe Execute browser_handle_dialog Accept or dismiss the currently open alert/confirm/prompt dialog in the active tab. Execute browser_hover Hover over element on page

All 17 YetiBrowser MCP tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about browser_page_state

What does the browser_page_state tool do? +

Extract form data, storage values, and cookies from the active page. It is categorised as a Read tool in the YetiBrowser MCP MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on browser_page_state? +

Register the YetiBrowser MCP server in PolicyLayer and add a rule for browser_page_state: 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 YetiBrowser MCP. Nothing to install.

What risk level is browser_page_state? +

browser_page_state is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit browser_page_state? +

Yes. Add a rate_limit block to the browser_page_state 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 browser_page_state completely? +

Set action: deny in the PolicyLayer policy for browser_page_state. 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 browser_page_state? +

browser_page_state is provided by the YetiBrowser MCP server (yetidevworks/yetibrowser-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every YetiBrowser MCP tool call.

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

CHECK YOUR STACK →