Is Cursor AI Safe for Sensitive Code? A 2026 Security Guide

Cursor is one of the fastest-growing AI coding tools of 2026. Its deep IDE integration and multi-file context window make it dramatically more capable than a tab-completion tool — and dramatically more capable of sending sensitive code to a third-party server. This guide explains what Cursor actually transmits, how to configure it to reduce that exposure, and where its data practices stand relative to the compliance frameworks that matter most for engineering teams in regulated industries.

What Cursor transmits and where it goes

Cursor is an Electron-based fork of VS Code that integrates AI completions, an AI chat panel (Cmd+K / Ctrl+K), and an AI codebase indexer. Understanding the data flow requires separating three distinct features:

Tab completions (Cursor Tab)

When Cursor Tab is enabled, Cursor sends the surrounding code context — typically hundreds of tokens before and after your cursor — to its backend servers to generate a completion. The model used is typically a fine-tuned version of a frontier model; as of 2026, Cursor uses its own fine-tuned completions model in addition to Claude and GPT-4o for different interaction types.

What gets sent: the code around your cursor, file-type metadata, and a session identifier. What does not get sent: your full codebase (unless explicitly configured for indexing — see below).

Chat (Cmd+K and the Sidebar)

The chat panel sends whatever you include in the conversation: your typed message, any files you attach (using @ mentions), and any code the model selects as context. This is the highest-risk feature because developers frequently paste log output, API responses, and error traces — which may contain production credentials, customer data, or PHI.

Codebase indexing

If you enable Cursor → Settings → Features → Codebase Indexing, Cursor uploads your entire codebase to Cursor's servers, indexes it for semantic search, and stores the embeddings. This gives Cursor context across files but means your proprietary code — including secrets in config files, embedded credentials, and internal business logic — is on a Cursor server.

Codebase indexing is the highest-risk feature for organizations with data loss prevention (DLP) policies. Disable it unless you have reviewed the data retention terms and confirmed it is acceptable.

Cursor's data and privacy policies in 2026

Cursor's published privacy policy and business terms (as of May 2026):

• Consumer and Pro tiers: Cursor may use data to improve its services. Prompts and code context are transmitted to Cursor's infrastructure and to underlying AI providers (Anthropic, OpenAI, Google) as a sub-processor.
• Business tier: Includes a DPA commitment; prompts are not used for training by default; sub-processor disclosure available; SOC 2 Type II audit available on request.
• Privacy mode: A setting in Cursor's preferences that disables training opt-in and prevents prompts from being used to improve the model. Privacy mode is on by default for Business accounts and optional for Pro.

BAA availability: As of 2026, Cursor does not offer a HIPAA BAA. This makes it unsuitable for workflows involving protected health information (PHI) regardless of tier.

SOC 2: Cursor (Anysphere Inc.) completed a SOC 2 Type II audit; report available under NDA to Business customers.

Is Cursor safer than GitHub Copilot?

The comparison depends on the feature you are evaluating:

| Feature | Cursor | GitHub Copilot Business | | --- | --- | --- | | Training opt-out | Yes (Privacy mode / Business tier) | Yes (org-level default) | | Codebase indexing | Yes (opt-in, but risky) | No equivalent feature | | Multi-file context in chat | Yes (@ mention files) | Limited (Copilot Chat with workspace context) | | BAA available | No | No (Copilot-specific BAA not available) | | SOC 2 Type II | Yes (Business tier) | Yes (GitHub) | | DPA | Yes (Business tier) | Yes (Copilot Business) |

For most regulated-industry use cases, the key differentiator is the codebase indexing feature: Cursor has it; Copilot does not. That makes Cursor higher-risk if indexing is left enabled.

See the companion post Source Code in AI Coding Assistants for a broader comparison of AI coding tools for security-conscious engineering teams. For healthcare developers specifically, see Is GitHub Copilot HIPAA Compliant? for the BAA and regulatory picture for the most common alternative.

Settings to configure before using Cursor with sensitive code

1. Disable codebase indexing

Cursor → Settings → Features → Codebase Indexing → Off

This is the single most important setting. Without indexing, Cursor can only see what you explicitly put in the chat window or what the tab completion engine samples as immediate context.

2. Enable Privacy mode

Cursor → Settings → General → Privacy Mode → Enabled

Privacy mode prevents Cursor from using your prompts to improve the model. On Business plans, it is on by default.

3. Review and limit @ context inclusions

When using the chat panel, be intentional about which files you @ mention. Never include:

• Config files (.env, config.yaml, secrets.json, anything that could contain API keys or database credentials)
• Log files from production systems (may contain PHI, customer PII, or session tokens)
• Files with hardcoded values from real environments

4. Use .cursorignore

Create a .cursorignore file in your repository root with patterns for sensitive paths. Cursor's tab completion and context window will exclude these files:

.env
.env.*
secrets/
config/production.yaml
*.pem
*.key

5. Configure your AI model backend

Business tier customers can configure which underlying model handles their requests. If your data agreement with a specific provider (Anthropic, OpenAI, Azure OpenAI) is stronger than others, route Cursor traffic to that provider.

Shadow AI risk with Cursor

One of the practical challenges of Cursor in enterprise environments is that it is not deployed centrally — developers install it on their own workstations. This creates the same shadow AI dynamic as consumer ChatGPT: the tool may be widely used before IT or security teams are aware of it.

Mitigation strategies:

• Browser/network proxy inspection: Some organizations inspect TLS traffic to detect and log connections to api.cursor.sh and upstream AI providers.
• Approved-software lists: Include Cursor on the list of tools that require IT approval, with configuration requirements (Privacy mode on, indexing off) as a condition of approval.
• Developer education: Most developers who enable codebase indexing do so for productivity, not to circumvent policy. Clear guidance on what to disable and why is more effective than a blanket prohibition that drives underground use.

Source code as sensitive data: what the compliance frameworks say

For engineering teams in regulated industries, source code itself is often a protected asset distinct from customer data:

• SOC 2 (Confidentiality criterion): Proprietary source code is typically classified as confidential information. Transmitting it to a third-party AI service without a contractual commitment to confidentiality may violate the Confidentiality criterion.
• ISO 27001: Under information classification controls (A.5.12), source code is typically classified at a level that restricts external transmission without authorization.
• Financial services (GLBA/FFIEC): Algorithms and models may be considered trade secrets; internal business logic exposed in code context may constitute nonpublic business information.
• Healthcare (HIPAA): Source code is not itself PHI, but code that contains hardcoded patient identifiers, test fixtures with real patient data, or system prompts that reference patient categories may contain or constitute PHI.

Frequently asked questions

Does Cursor sell or share my code?

Cursor's published terms state that they do not sell user code. On Business plans with Privacy mode, code is also not used to train models. As a sub-processor, Cursor transmits context to OpenAI, Anthropic, or Google — the underlying model providers — subject to those providers' zero-data-retention or no-training terms for API traffic. Read the Cursor DPA for your tier to understand the full sub-processor chain.

Is Cursor safe for closed-source commercial software?

For most commercial software development, Cursor Business with Privacy mode on and codebase indexing off is a defensible configuration. The risk is that your code context (the snippet around the cursor and whatever you paste into chat) is transmitted to Cursor's servers and underlying AI providers for inference. If your IP policy requires all code to remain on-premises, Cursor is not the right tool — consider a local model setup instead.

Can I use Cursor for healthcare software development?

You can use Cursor to write healthcare software. The restriction is on sending PHI through Cursor. If your development workflow involves real patient data in test fixtures, log files, or sample API responses, those should be replaced with synthetic data before being pasted into Cursor. Cursor does not have a HIPAA BAA, so any prompt containing real PHI creates a compliance exposure.

What is the difference between Cursor's Privacy mode and disabling chat history?

Privacy mode controls whether Cursor uses your prompts to improve its models — it prevents training use. Disabling chat history (available in the sidebar) removes the visible history from the Cursor UI but does not change transmission or retention behavior on Cursor's servers. For compliance purposes, the relevant setting is Privacy mode (and the retention terms in your DPA), not the UI history toggle.

How does Cursor handle API keys and secrets in code?

Cursor does not specifically detect or suppress API keys and secrets. If your code includes a .env file with real credentials and you @ mention that file in the chat, those credentials are transmitted to Cursor's servers. Use .cursorignore to exclude credential files, and prefer environment-variable references over hardcoded values in the files you share with AI tools. A named entity recognition (NER) or secret-scanning tool at the IDE level can provide an additional safety layer.

Is there a self-hosted version of Cursor?

As of 2026, Cursor does not offer a self-hosted option. Teams that require on-premises or fully private AI code assistance should evaluate: VS Code with Continue.dev + a local Ollama model, JetBrains AI with a self-hosted model, or Amazon Q Developer with a private CodeWhisperer endpoint. These alternatives sacrifice some capability for full control over data. See Sonomos vs. self-hosted AI for a breakdown of what running a local model does and doesn't solve from a data-protection standpoint.

The bottom line

Cursor is one of the most capable AI coding environments available in 2026, and many engineering teams in regulated industries use it productively. The risks are manageable with the right configuration: disable codebase indexing, enable Privacy mode, use .cursorignore for sensitive paths, and build synthetic test data into your development workflow so that real production data never appears in AI prompts. For teams where those controls are insufficient — healthcare teams with strict PHI containment, firms whose IP policies require full on-premises processing, or environments where shadow-AI governance is a priority — local model setups or on-premises alternatives are the better fit.