# RuntimeError: The session cookie is not marked as secure. This is a security issue. Please set SESSION_COOKIE_SECURE to True in production.

- **ID:** `python/flask-session-cookie-secure-error`
- **Domain:** python
- **Category:** config_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Flask warns or errors when running in production without a secure cookie setting.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **** (100% success)
   ```
   Set app.config.update(SESSION_COOKIE_SECURE=True, SESSION_COOKIE_HTTPONLY=True)
   ```
2. **** (90% success)
   ```
   Use environment variables to toggle secure cookies based on environment: app.config['SESSION_COOKIE_SECURE'] = os.getenv('FLASK_ENV') == 'production'
   ```

## Dead Ends

- **** — This exposes session cookies over HTTP, leading to security vulnerabilities. (90% fail)
- **** — In some Flask versions, this may become an error or cause security audit failures. (70% fail)