Playbook Updated January 2026

Agentic Browser Security Playbook

A practical guide to securing AI-driven browsing, summarization, and task automation. Use this playbook to reduce prompt injection risk and prevent cross-site data leakage.

Threat Model

  • Untrusted content: web pages, forums, documents, and user-generated content.
  • Private context: logged-in sessions, email, internal portals.
  • Action tooling: agents that can click, navigate, and submit forms.

Core Controls

  • Context separation: segregate untrusted content from tool instructions.
  • Action gating: require explicit approval for cross-site actions.
  • Session isolation: use separate browser profiles for agents.
  • Output filtering: block sensitive data from being exfiltrated or echoed.

Detection and Monitoring

  • Alert on unexpected navigation to account settings or credential pages.
  • Log agent tool calls with full context and policy decisions.
  • Track outbound requests to newly registered or low-reputation domains.

Incident Response Checklist

  1. Disable agentic browsing for impacted users or groups.
  2. Rotate credentials for any accounts accessed by the agent.
  3. Review agent logs for cross-site actions and data access.
  4. Harden policies to require confirmations for high-risk actions.

Implementation Checklist

Policy

  • Define allowed domains and actions.
  • Block actions on sensitive domains by default.
  • Require user confirmation for privileged steps.

Technical Controls

  • Use a dedicated agent browser profile.
  • Disable unneeded extensions and autofill.
  • Limit cookie scope and session persistence.

Need a Deployment Plan?

AARSM can help deploy runtime guardrails for agentic browsers across your organization.