Webhook Security: A Complete Guide

Webhook security is often overlooked — until something goes wrong. Here is everything you need to secure your webhook endpoints.

HMAC Signatures

Every webhook should be signed with HMAC-SHA256. The receiver verifies the signature using a shared secret.

Replay Attack Prevention

Include a timestamp in the signature. Reject webhooks with timestamps older than 5 minutes.

IP Whitelisting

Restrict webhook sources to known IP addresses. HookSniff provides a /v1/outbound-ips endpoint.

TLS

Always use HTTPS. Never accept webhooks over plain HTTP.

Rate Limiting

Protect your endpoints from webhook floods. HookSniff supports per-endpoint throttling.

Input Validation

Validate webhook payloads against a JSON schema. HookSniff's schema registry handles this.

Monitoring

Alert on unusual patterns — spike in volume, new IP addresses, failed signatures.