Claude Code
ui
XSS Vulnerability in Template Output
User-provided content displayed in template without escaping. Attacker can inject malicious JavaScript that executes in other users' browsers. Form submissions, comments, or user profiles become attack vectors.
Template renders user input directly, trusting it's safe when it's not.
Error Messages You Might See
XSS vulnerability detected in template
Malicious script executed in user context
Script injection through unsanitized output
Common Causes
- Raw HTML output without escaping: {{ userInput }} instead of properly escaped
- dangerouslySetInnerHTML or equivalent used without validation
- Server trust user input without sanitizing
- Missing Content Security Policy headers
- Frontend sanitization only, no backend validation
How to Fix It
Escape all user input by default. Use framework features: React auto-escapes, use innerText not innerHTML. Sanitize HTML: DOMPurify library on frontend. Backend validation required too. Use Content Security Policy header to block inline scripts. Never use dangerouslySetInnerHTML unless absolutely necessary and content is verified safe.
Real developers can help you.
Dor Yaloz
SW engineer with 6+ years of experience,
I worked with React/Node/Python
did projects with React+Capacitor.js for ios
Supabase expert
Kingsley Omage
Fullstack software engineer passionate about AI Agents, blockchain, LLMs.
Milan Surelia
Milan Surelia is a Mobile App Developer with 5+ years of experience crafting scalable, cross-platform apps at 7Span and Meticha. At 7Span, he engineers feature-rich Flutter apps with smooth performance and modern UI. As the Co-Founder of Meticha, he builds open-source tools and developer-focused products that solve real-world problems.
Expertise:
💡 Developing cross-platform apps using Flutter, Dart, and Jetpack Compose for Android, iOS, and Web.
🖋️ Sharing insights through technical writing, blogging, and open-source contributions.
🤝 Collaborating closely with designers, PMs, and developers to build seamless mobile experiences.
Notable Achievements:
🎯 Revamped the Vepaar app into Vepaar Store & CRM with a 2x performance boost and smoother UX.
🚀 Launched Compose101 — a Jetpack Compose starter kit to speed up Android development.
🌟 Open source contributions on Github & StackOverflow for Flutter & Dart
🎖️ Worked on improving app performance and user experience with smart solutions.
Milan is always happy to connect, work on new ideas, and explore the latest in technology.
Taufan
I’m a product-focused engineer and tech leader who builds scalable systems and turns ideas into production-ready platforms.
Over the past years, I’ve worked across startups and fast-moving teams, leading backend architecture, improving system reliability, and shipping products used by thousands of users. My strength is not just writing code — but connecting product vision, technical execution, and business impact.
Stanislav Prigodich
15+ years building iOS and web apps at startups and enterprise companies. I want to use that experience to help builders ship real products - when something breaks, I'm here to fix it.
Luca Liberati
I work on monoliths and microservices, backends and frontends, manage K8s clusters and love to design apps architecture
Daniel Vázquez
Software Engineer with over 10 years of experience on Startups, Government, big tech industry & consulting.
Costea Adrian
Embedded Engineer specilizing in perception systems. Latest project was a adas camera calibration system.
Yovel Cohen
I got a lot of experience in building Long-horizon AI Agents in production, Backend apps that scale to millions of users and frontend knowledge as well.
Basel Issmail
’m a Senior Full-Stack Developer and Tech Lead with experience designing and building scalable web platforms. I work across the full development lifecycle, from translating business requirements into technical architecture to delivering reliable production systems.
My work focuses on modern web technologies, including TypeScript, Angular, Node.js, and cloud-based architectures. I enjoy solving complex technical problems and helping teams turn product ideas and prototypes into working platforms that can grow and scale.
In addition to development, I often collaborate closely with product managers, business analysts, designers, and QA teams to ensure that solutions align with both technical and business goals.
I enjoy working with startups and product teams where I can contribute both as a hands-on engineer and as a technical partner in designing and delivering impactful software.
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
How to prevent XSS in React?
React auto-escapes by default. Avoid: dangerouslySetInnerHTML. For HTML content, use DOMPurify: purify.sanitize(html)
What's Content Security Policy?
HTTP header restricts script execution: Content-Security-Policy: script-src 'self'. Blocks inline scripts and external URLs.