code-review 2026

I have reviewed the get_user_data function against the five-axis quality standard. The implementation has significant security and correctness issues.

Review: User Data API Endpoint

Correctness

• Change matches spec
• Edge cases handled
• Error paths handled
• Tests adequate

Security

• No secrets in code
• Input validated
• No injection vulnerabilities
• Auth checks
• External data treated as untrusted

Findings

Critical: SQL Injection vulnerability. The user_id is concatenated directly into the query string. Use parameterized queries instead.
Required: Input validation is missing. There is no check to ensure user_id is a valid format or exists before execution.
Required: Error handling is missing. If the database connection fails or the query returns no results, the application may crash or return an unhandled exception.
Nit: Use a more descriptive variable name than res to improve readability (e.g., user_records).

Implementation Suggestion

def get_user_data(user_id: str):
    try:
        # Use parameterized query to prevent SQL injection
        query = "SELECT id, username, email FROM users WHERE id = ?"
        cursor = db.execute(query, (user_id,))
        record = cursor.fetchone()
        
        if not record:
            return None
        return record
    except DatabaseError as e:
        logger.error(f"Failed to fetch user {user_id}: {e}")
        raise APIError("Internal Database Error")

Verdict

• Approve
• Request changes — The SQL injection vulnerability must be fixed before this code is merged.

Next steps

1. Implement parameterized queries for all database interactions.
2. Add a global error handler or local try-except block for database exceptions.
3. Add a unit test specifically targeting the SQL injection vector.