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Payload Ecommerce is a plugin ecosystem for Payload CMS.
The advisory affects deployments using @payloadcms/plugin-ecommerce.
The vulnerable path requires the Stripe payment adapter.
Deployments without the Stripe payment flow are not affected.
The core issue is order confirmation validation.
An order confirmation can be processed more than once under certain conditions.
This is a duplicate-processing class of vulnerability.
Stripe sends payment and checkout events to the application.
The adapter maps those events into order confirmation logic.
If the same event or equivalent event is delivered twice, confirmation may run twice.
Webhook retries can cause repeated delivery.
Concurrent webhook handling can also create a race window.
The advisory states it happens under certain conditions.
It does not publish a full proof of concept in the provided text.
The impact is high because order state may be mutated repeatedly.
Duplicate confirmation may trigger duplicate fulfillment workflows.
It may also cause duplicate emails or inventory changes.
Payment state may become inconsistent with order state.
The issue is in the integration layer, not all Payload CMS installs.
Affected package versions are < 3.90.0.
Also affected are >= 4.0.0-canary.0 and < 4.0.0-canary.34.
Patched versions are 3.90.0 and 4.0.0-canary.34.
The advisory was published Sep 18, 2026.
It was reviewed and updated Oct 6, 2026.
GitHub reviewed the advisory.
The severity is high.
The vulnerability type is an order confirmation validation issue.
No CVE identifier is provided in the supplied .
The workaround is to ensure Stripe order confirmations can only be processed once.
Upgrading to a patched version is the recommended fix.
Temporary mitigation should not replace upgrade.
Validate event IDs and store processed confirmations.
Enforce idempotency around order confirmation.
Lock order records during confirmation.
Reject already-confirmed orders.
Verify Stripe event signatures and amounts.
Monitor duplicate webhook deliveries.
Audit orders for repeated confirmations.
Apply patches as soon as possible.
Test Stripe webhook retry behavior.
DailyCVE Form:
Platform: Payload Ecommerce
Version: <3.90.0, canary<34
Vulnerability: Duplicate order confirmation
Severity: High
date: Sep 18, 2026
Prediction: Oct 6, 2026
(end of form)
What Undercode Say:
Analytics:
npm ls @payloadcms/plugin-ecommerce npm view @payloadcms/plugin-ecommerce versions --json npm audit
{
"dependencies": {
"@payloadcms/plugin-ecommerce": "3.89.0"
}
}
// Stripe webhook idempotency guard
const processed = await db.processedEvents.findOne({ eventId: event.id });
if (processed) return Response.json({ received: true });
await db.processedEvents.insert({ eventId: event.id });
const order = await db.orders.findOne({ stripeSessionId: session.id });
if (order?.confirmed) return Response.json({ received: true });
await confirmOrder(order.id);
Exploit: (Educational Purposes!)
Simulate repeated Stripe webhook delivery in a test environment stripe trigger checkout.session.completed stripe trigger checkout.session.completed
// Educational duplicate-confirmation test against a local fixture
await fetch("/api/stripe/webhook", {
method: "POST",
headers: { "stripe-signature": testSignature },
body: sameStripeEvent
});
await fetch("/api/stripe/webhook", {
method: "POST",
headers: { "stripe-signature": testSignature },
body: sameStripeEvent
});
Protection: from this CVE
npm install @payloadcms/[email protected] or npm install @payloadcms/[email protected]
// Enforce one confirmation per Stripe event/order if (await isEventProcessed(event.id)) return ok(); if (await isOrderConfirmed(order.id)) return ok(); await markEventProcessed(event.id); await confirmOrderOnce(order.id);
Impact:
Duplicate order confirmations.
Duplicate fulfillment and notifications.
Order/payment state inconsistency.
Inventory or enment errors.
High severity if Stripe flow used.
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Sources:
Reported By: github.com
Extra Source Hub:
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