They create identity risk because they can sit inside the authenticated session and see the same bearer tokens the user relies on. That means an apparently harmless productivity add-on can become a credential interception path, especially when it has access to web application runtime state and connected services.
Why This Matters for Security Teams
Browser-based AI extensions are not just another productivity layer. They operate inside the same authenticated browser session as the user, which means they can observe page content, session context, and sometimes tokens or headers that were never meant to leave the browser. That makes them materially different from ordinary add-ons: they can become an identity bridge between human intent and enterprise systems.
The risk is amplified because browser controls rarely distinguish between a trusted employee action and an extension acting on the employee’s behalf. Once an extension can read, modify, or relay web requests, it may inherit access that security teams assumed was limited to the user. NIST’s Cybersecurity Framework 2.0 stresses governance and access control, but browser extension identity exposure often sits outside standard IAM review cycles.
NHIMG research on NHI abuse shows how quickly exposed credentials are operationalised by attackers, and the same dynamic applies when extensions surface bearer tokens or API keys in the browser. In practice, many security teams encounter extension-driven identity leakage only after session abuse, data exfiltration, or unsanctioned tool access has already occurred, rather than through intentional review.
How It Works in Practice
Identity risk emerges when an AI extension is granted permissions that are broader than its business need. The extension may read active tabs, inspect DOM content, observe clipboard events, or interact with web app APIs. If the browser session already holds SSO tokens, refresh tokens, or other bearer artifacts, the extension can become an indirect path to those credentials even if the user never intended to share them.
This is why browser-based AI tools should be assessed as non-human identities with a privileged runtime footprint, not as harmless UI helpers. NHIMG’s Ultimate Guide to NHIs highlights how weak visibility and excessive privilege are common identity failures, and those patterns repeat inside browser ecosystems. A practical control set usually includes:
- Least-privilege extension approval based on exact browser permissions, not vendor intent.
- Segregated browser profiles for admin workflows, finance, and general browsing.
- Blocking extensions from sensitive domains unless explicitly reviewed.
- Monitoring for token-bearing requests, unusual API calls, and extension-install drift.
- Session hardening, including short-lived tokens and re-authentication for high-risk actions.
Where possible, enterprises should treat the extension as a workload identity with constrained runtime authority, then enforce policy at the browser, proxy, and application layers. Current guidance suggests that this is stronger than relying on user awareness alone. The browser extension control model in 52 NHI Breaches Analysis also reflects a repeated pattern: identity compromise often starts with over-trusted tooling rather than direct account takeover. These controls tend to break down when extensions are allowed in unmanaged browsers because administrators lose visibility into permissions, updates, and the actual data paths the extension can inspect.
Common Variations and Edge Cases
Tighter extension control often increases friction for users, so organisations must balance usability against identity exposure. That tradeoff is especially sharp in teams that rely on AI assistants for drafting, search, or code review, because blanket blocking can push users toward shadow IT. The better approach is selective allowance with explicit risk tiers.
There is no universal standard for browser AI extension governance yet. Best practice is evolving, but current guidance generally supports three cases: fully approved extensions on low-risk profiles, restricted extensions on monitored workstations, and no-extension zones for privileged or regulated workflows. In those zones, even read-only access can be dangerous if the extension can infer tokens, prompt content, or internal application state.
Edge cases include remote desktop sessions, shared kiosks, and contractor environments where browser state persists across users. Those environments are particularly difficult because the extension may inherit one user’s session and expose another user’s data path. For deeper NHI context, the Top 10 NHI Issues and JetBrains GitHub plugin token exposure illustrate how trusted developer tooling can become an identity leak path when permissions exceed operational need.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Agentic AI Top 10 and CSA MAESTRO address the attack and risk surface, while NIST AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Agentic AI Top 10 | A1 | Browser AI extensions act autonomously inside user sessions and can abuse granted tool access. |
| CSA MAESTRO | TRUST-03 | Maestro addresses trust boundaries and runtime control for agentic software in browsers. |
| NIST AI RMF | AI RMF applies to governance of AI-enabled extensions that can affect identity and access. |
Assign ownership, assess risk, and monitor AI extension behaviour as part of enterprise AI governance.
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on June 10, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org