Replit auth

CSRF Token Bypass on Replit

CSRF attacks succeed despite enabled CSRF protection. Malicious sites can perform unauthorized actions.

CSRF tokens not properly validated or exempt endpoints allow attacks.

Error Messages You Might See

Invalid CSRF token Missing CSRF token
Invalid CSRF tokenMissing CSRF token

Common Causes

  1. CSRF exemption too broad (e.g., /api/**)
  2. Token not validated on POST/PUT/DELETE
  3. Cookie-based sessions with permissive domain
  4. Token not included in form or header
  5. SameSite cookie attribute not set

How to Fix It

Keep CSRF enabled by default, exempt only /webhook paths if needed. Use httpOnly cookies for CSRF tokens. Set SameSite=Strict: Set-Cookie: ...; SameSite=Strict. Include token in forms: . Validate referer header for sensitive operations.

Real developers can help you.

Matthew Butler Matthew Butler Systems Development Engineer @ Amazon Web Services Daniel Vázquez Daniel Vázquez Software Engineer with over 10 years of experience on Startups, Government, big tech industry & consulting. Anthony Akpan Anthony Akpan Developer with 8 years of experience building softwares fro startups Taufan 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. Yovel Cohen 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. Richard McSorley Richard McSorley Full-Stack Software Engineer with 8+ years building high-performance applications for enterprise clients. Shipped production systems at Walmart (4,000+ stores), Cigna (20M+ users), and Arkansas Blue Cross. 5 patents in retail/supply chain tech. Currently focused on AI integrations, automation tools, and TypeScript-first architectures. Bastien Labelle Bastien Labelle Full stack dev w/ 20+ years of experience Prakash Prajapati Prakash Prajapati I’m a Senior Python Developer specializing in building secure, scalable, and highly available systems. I work primarily with Python, Django, FastAPI, Docker, PostgreSQL, and modern AI tooling such as PydanticAI, focusing on clean architecture, strong design principles, and reliable DevOps practices. I enjoy solving complex engineering problems and designing systems that are maintainable, resilient, and built to scale. legrab legrab I'll fill this later Antriksh Narang Antriksh Narang 5 years+ Experienced Dev (Specially in Web Development), can help in python, javascript, react, next.js and full stack web dev technologies.

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

Get Help

Frequently Asked Questions

How do I include CSRF token in Thymeleaf?

<input type="hidden" th:name="${_csrf.parameterName}" th:value="${_csrf.token}">

Which endpoints need CSRF protection?

All POST/PUT/DELETE that modify data. GET is read-only and doesn't need token

Related Replit Issues

Can't fix it yourself?
Real developers can help.

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

Get Help