Lovable
security
XSS Vulnerability in Lovable App User Input
Your Lovable app displays user-submitted content (comments, profile names, form inputs) without properly sanitizing it. This allows attackers to inject malicious JavaScript that runs in other users' browsers.
Cross-site scripting (XSS) is a serious vulnerability that can steal user sessions, redirect users to phishing sites, or modify what your app displays. If your app has any feature where one user's input is shown to another user, it may be vulnerable.
The issue often goes unnoticed until someone submits a script tag in a form field and it executes, or until your app is flagged in a security scan.
Error Messages You Might See
Content Security Policy violation
Refused to execute inline script
Unsafe HTML content detected
Common Causes
- Using dangerouslySetInnerHTML — Lovable may generate React code that renders user content as raw HTML
- No input sanitization — User input is stored and displayed exactly as entered, including HTML and script tags
- Template literals in DOM — User data inserted into the page using template strings without escaping
- Missing Content-Security-Policy headers — No CSP headers to prevent inline script execution
How to Fix It
- Never use dangerouslySetInnerHTML with user data — Replace it with regular text rendering that auto-escapes HTML
- Install DOMPurify — If you must render HTML, use a sanitization library like DOMPurify to strip malicious content
- Add Content-Security-Policy headers — Configure CSP headers to prevent inline script execution
- Validate and sanitize on the server — Clean user input before storing it in the database, not just when displaying it
- Test with common XSS payloads — Try submitting <script>alert('xss')</script> in your form fields to verify they're safe
Real developers can help you.
hanson1014
Full-stack developer experienced in fixing and deploying AI-generated apps from Lovable, Bolt.new, Cursor, and Replit. I specialize in debugging Supabase integration issues (auth flows, RLS policies, database connections), fixing broken deployments, resolving routing/blank screen problems, and cleaning up messy React/Vite codebases. I also build production apps with the Claude API and have shipped a Mac desktop dev tool (Nexterm from scratch. Based in Hong Kong, fast turnaround.
Matthew Jordan
I've been working at a large software company named Kainos for 2 years, and mainly specialise in Platform Engineering. I regularly enjoy working on software products outside of work, and I'm a huge fan of game development using Unity. I personally enjoy Python & C# in my spare time, but I also specialise in multiple different platform-related technologies from my day job.
AUXLE
I am a Full Stack Developer experienced in building Websites, Web apps and Cross Platform Mobile Apps for Startups and Companies.
zipking
I am a technologist and product builder dedicated to creating high-impact solutions at the intersection of AI and specialized markets. Currently, I am focused on PropScan (EstateGuard), an AI-driven SaaS platform tailored for the Japanese real estate industry, and exploring the potential of Archify.
As an INFJ-T, I approach development with a "systems-thinking" mindset—balancing technical precision with a deep understanding of user needs. I particularly enjoy the challenge of architecting Vertical AI SaaS and optimizing Small Language Models (SLMs) to solve specific, real-world business problems. Whether I'm in a CTO-level leadership role or hands-on with the code, I thrive on building tools that turn complex data into actionable value.
Jared Hasson
Full time lead founding dev at a cyber security saas startup, with 10 yoe and a bachelor's in CS. Building & debugging software products is what I've spent my time on for forever
Matthew Butler
Systems Development Engineer @ Amazon Web Services
Antriksh Narang
5 years+ Experienced Dev (Specially in Web Development), can help in python, javascript, react, next.js and full stack web dev technologies.
Daniel Vázquez
Software Engineer with over 10 years of experience on Startups, Government, big tech industry & consulting.
Caio Rodrigues
I'm a full-stack developer focused on building practical and scalable web applications. My main experience is with **React, TypeScript, and modern frontend architectures**, where I prioritize clean code, component reusability, and maintainable project structures.
I have strong experience working with **dynamic forms, state management (Redux / React Hook Form), and complex data-driven interfaces**. I enjoy solving real-world problems by turning ideas into reliable software that companies can actually use in their daily operations.
Beyond coding, I care about **software quality and architecture**, following best practices for componentization, code organization, and performance optimization.
I'm also comfortable working across the stack when needed, integrating APIs, handling business logic, and helping transform prototypes into production-ready systems.
My goal is always to deliver solutions that are **simple, efficient, and genuinely useful for the people using them.**
ISHANTDEEP SINGH
Senior Software Engineer with 7+ years of experience in React, JavaScript, TypeScript, Next.js, and Node.js. I’ve also worked as a tech lead for startups, owning end-to-end technical execution including architecture, development, scaling, and delivery. I bring a strong mix of hands-on coding, product thinking, and technical leadership, and I’m comfortable building products from scratch as well as improving and scaling existing systems.
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
What is XSS and why is it dangerous?
Cross-site scripting (XSS) allows attackers to inject malicious scripts into your app. When other users visit the page, the script runs in their browser and can steal their login sessions, personal data, or redirect them to fake sites.
Can React prevent XSS automatically?
React escapes content by default when you use JSX expressions like {userInput}. However, using dangerouslySetInnerHTML or inserting content via DOM manipulation bypasses this protection.