PAY-003critical SeverityPayment Processing & Webhook Integrity
customer.subscription.deleted Handled to Revoke Access
AI boilerplate handles checkout.session.completed but forgets customer.subscription.deleted, leaving cancelled users on paid tiers indefinitely.
1-Click Fix Prompt for Cursor & Claude Code
Review my codebase for "customer.subscription.deleted Handled to Revoke Access" (PAY-003). Issue: AI boilerplate handles checkout.session.completed but forgets customer.subscription.deleted, leaving cancelled users on paid tiers indefinitely. Remediation required: Implement an explicit handler for customer.subscription.deleted that downgrades user entitlements immediately. Please: 1. Locate any occurrences of this issue across my repository. 2. Refactor the code to follow production standards without breaking existing functionality. 3. Provide a clear command or step to test and verify the fix.
Why AI Assistants Write This Bug
AI boilerplate handles checkout.session.completed but forgets customer.subscription.deleted, leaving cancelled users on paid tiers indefinitely.
AI code generation prioritizes immediate syntax execution over production edge cases. When an assistant hits an undefined variable or strict type error, it frequently takes the path of least resistance rather than implementing standard pre-launch security patterns.
Code Comparison
Common AI Code PatternVulnerable
// Vulnerable AI-generated pattern for: customer.subscription.deleted Handled to Revoke Access
// Flawed Stripe webhook handler
export async function POST(req: Request) {
const body = await req.json(); // BUG: Fails signature verification!
const signature = req.headers.get("stripe-signature");
// Unhandled events drop silently
return Response.json({ received: true });
}Launch-Ready Fix
// Production-ready fix for: customer.subscription.deleted Handled to Revoke Access
// Fixed Stripe webhook with raw text buffer
export async function POST(req: Request) {
const body = await req.text(); // Raw text preserves HMAC signature
const signature = req.headers.get("stripe-signature");
const event = stripe.webhooks.constructEvent(body, signature!, process.env.STRIPE_WEBHOOK_SECRET!);
// Acknowledge receipt with 200
return Response.json({ received: true }, { status: 200 });
}Remediation & Verification Checklist
Remediation: Implement an explicit handler for customer.subscription.deleted that downgrades user entitlements immediately.
- Search your codebase for pattern matching "customer.subscription.deleted Handled to Revoke Access".
- Apply the recommended remediation: Implement an explicit handler for customer.subscription.deleted that downgrades user entitlements immediately.
- Run local build and test commands to ensure no regressions.
- Verify in your browser or with curl that the issue is resolved.
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