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MEDIUM

APIFold Vulnerable to Unauthenticated Webhook Event Injection

Published Jul 23, 2026

Description

APIFold reads an OpenAPI 3.x or Swagger 2.x specification and generates a live, production-ready MCP server endpoint. Prior to commit 7f19b52280f414f57af2b79a95333d1c8fbeece5, the `/webhooks/:serverSlug/:eventName` endpoint accepts arbitrary unauthenticated JSON and stores it in Redis and the `webhook_events` PostgreSQL table without any signature check or authentication requirement. The root cause is that `createWebhookRouter` is called at `server.ts:188` without a `validators` map, so `receivers.ts:80`'s optional-chaining guard evaluates to `undefined` and the signature-validation block (`receiver.ts:81–95`) is unconditionally skipped. Any unauthenticated network client that knows a valid server slug can inject arbitrary payloads, which are subsequently served as trusted resource state to legitimate MCP clients. Commit 7f19b52280f414f57af2b79a95333d1c8fbeece5 patches the issue.

Affected products

Remediation

No remediation recorded yet.

References (4)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner GitHub_M
Published Jul 23, 2026
Updated Jul 23, 2026
Reserved May 19, 2026
CISA Vulnrichment
Updated Jul 23, 2026
NVD
Status Deferred
Modified Jul 23, 2026
Red Hat
Severity n/a
Public date n/a
ENISA EUVD
Assigner GitHub_M
Published Jul 23, 2026
Updated Jul 23, 2026
Exploited since n/a
EUVD-2026-48338