Windsurf api

Cascade Broke Webhook Signature Validation

Webhook signature validation is broken after Cascade refactored the verification code. This is a critical security issue - spoofed webhooks from attackers are being accepted as legitimate. Stripe or other webhook payloads are not being verified before processing.

Cascade likely removed or modified the signature verification logic during refactoring.

Error Messages You Might See

Webhook signature invalid HMAC verification failed Signature mismatch Webhook authenticity could not be verified
Webhook signature invalidHMAC verification failedSignature mismatchWebhook authenticity could not be verified

Common Causes

  1. Cascade removed HMAC-SHA256 signature verification from webhook handler
  2. Webhook secret changed without updating verification code
  3. Cascade removed timestamp validation preventing replay attacks
  4. Algorithm mismatch in signature generation vs verification

How to Fix It

Implement webhook signature verification immediately. Verify request body signature against webhook secret using HMAC-SHA256. Validate timestamp is recent (within 5 minutes) to prevent replay attacks. Verify algorithm used matches webhook provider documentation. Test with invalid signature to ensure rejection.

Real developers can help you.

Matt Butler Matt Butler Software Engineer @ AWS Luca Liberati Luca Liberati I work on monoliths and microservices, backends and frontends, manage K8s clusters and love to design apps architecture Victor Denisov Victor Denisov Developer 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. Rudra Bhikadiya Rudra Bhikadiya I build and fix web apps across Next.js, Node.js, and DBs. Comfortable jumping into messy code, broken APIs, and mysterious bugs. If your project works in theory but not in reality, I help close that gap. Jared Hasson 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 Jen Jacobsen Jen Jacobsen I’m a Full-Stack Developer with over 10 years of experience building modern web and mobile applications. I enjoy working across the full product lifecycle — turning ideas into real, well-built products that are intuitive for users and scalable for businesses. I particularly enjoy building mobile apps, modern web platforms, and solving complex technical problems in a way that keeps systems clean, reliable, and easy to maintain. Bastien Labelle Bastien Labelle Full stack dev w/ 20+ years of experience Mehdi Ben Haddou Mehdi Ben Haddou - Founder of Chessigma (1M+ users) & many small projects - ex Founding Engineer @Uplane (YC F25) - ex Software Engineer @Amazon and @Booking.com Simon A. Simon A. I'm a backend developer building APIs, emulators, and interactive game systems. Professionally, I've developed Java/Spring reporting solutions, managed relational and NoSQL databases, and implemented CI/CD workflows.

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Frequently Asked Questions

How do I verify Stripe webhooks?

Use stripe.webhooks.constructEvent() with endpoint secret. Catches signature verification and parsing.

What timestamp validation should I do?

Verify t parameter is within last 5 minutes to prevent replay. Check against current system time.

Related Windsurf Issues

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