# Security Policy

## Supported versions

| Version | Supported |
| --- | --- |
| 1.x | Yes |
| < 1.0 | No |

The plugin is a local DSH Desktop bundle. It runs with the same OS user privileges as DeepSeek Harness and is not sandboxed by the plugin system itself.

## Reporting a vulnerability

Please do **not** open a public issue for a vulnerability that exposes credentials, allows guest-to-host code execution, or bypasses the Electron webview boundary.

Use the repository's **Security → Report a vulnerability** flow (GitHub private advisory). Include:

- DSH Desktop version and OS.
- Steps to reproduce.
- Whether the issue involves the host document, the embedded DeepSeek guest, or the Desktop browser bridge.
- Any relevant console output with tokens redacted.

Please allow time for a fix before public disclosure.

## Design boundaries

- **No Host HTTP routes.** The Host half (`index.js`) exports an empty `apply()`.
- **No Harness credentials in the guest.** The plugin never reads or forwards an API key, Harness session token, or account token.
- **Isolated webview.** The guest is attached through the Desktop browser bridge with sandboxing, context isolation, no Node integration and no webviewTag. Permission, device and display-media requests are denied by the host policy.
- **No HTML injection from the guest.** Results from the guest are limited to fixed console markers and boolean checks; guest markup is never inserted into the Harness document.
- **Local token storage.** The DeepSeek web sign-in is stored in the DSH renderer's `localStorage` under `dsh.deepseek-web.auth.v1`. It is plaintext and has the same exposure as other DSH browser storage. On launch it is copied into the DeepSeek origin's `localStorage` on a same-origin warmup page before the chat app boots; the plugin does not send it anywhere.
- **Environment-warning preference.** Before the chat app boots, the plugin sets DeepSeek's own `closeUnsafeEnvWarn` preference on a same-origin warmup page. This is the state its “dismiss” X button writes, and it prevents the “abnormal usage environment” advisory from reappearing on every launch. It does not spoof the User-Agent, bypass authentication, or change isolation; it does dismiss a third-party security advisory, and the embedded page remains non-official.
- **No telemetry.** The plugin does not send analytics or call any third-party API of its own.

## Third-party content

The embedded page is `https://chat.deepseek.com/`, owned and operated by DeepSeek. The plugin does not control its content, availability, authentication flow or privacy policy. Review DeepSeek's terms and privacy policy before signing in.

## Local data

To remove the saved web sign-in from the DSH renderer:

```js
localStorage.removeItem('dsh.deepseek-web.auth.v1')
```

Removing the plugin does not remove data that DeepSeek's own web page stored in its webview partition; that partition is process-scoped and is discarded when the app exits.

## Dependency surface

There are no runtime npm dependencies. The repository's check script uses only Node built-ins. CI uses GitHub Actions and Node.js.