I keep seeing threads about running Cursor in TEEs or local LLMs to stop data exfiltration. That's a massive overcomplication for most corporate environments. The threat model is data leaving your network to Cursor's cloud. The primary mitigation is controlling that egress.

You don't need magic hardware. You need a firewall policy and a proxy.

**First, understand what you're blocking.** Cursor's primary domains are `cursor.sh` and `*.cursor.sh`. You also need to consider its dependencies, like OpenAI or Anthropic if you're using their AI features, but the principle is the same: deny all, allow known-good.

A basic but effective stance for a high-security segment (e.g., developer VLAN) is to whitelist only your internal tools and block everything else, making exceptions after review. For Cursor, you'd create an explicit rule.

Example simple network ACL logic (conceptual):
```
Rule 1: Allow -> Internal package repos, internal APIs
Rule 2: Allow -> Specific external SaaS (e.g., github.com)
Rule 3: Deny -> *
```
Cursor wouldn't work under this. To enable it, you'd add an explicit `DENY` rule for `*.cursor.sh` and `*.openai.com` (or equivalent). No traffic, no data leak.

**The real work is in the monitoring, not the blocking.** You set the deny rule, then you watch your outbound proxy logs for attempts to hit those domains. That's your early warning signal.

```
# Example log alert (pseudo Splunk)
index=proxy_ssl dest_domain="*.cursor.sh" action=denied
| stats count by src_ip, user
| where count > threshold
```
That log tells you who's trying to use Cursor against policy. Your incident is now a local HR/compliance issue, not a catastrophic data spill.

Enclaves add complexity for a problem that is, at its core, a network flow issue. If you can't trust your network filtering to stop unauthorized data flows, you have bigger problems than your IDE. Focus on nailing the egress controls and audit trails first. That covers the vast majority of the risk.