Webhook forgery risks for payment providers

A forged webhook can mark a payout as settled, unlock a merchant account, or trigger a refund. Providers who accept unsigned or HMAC-weak callbacks invite exactly that class of abuse.

Replay protection matters as much as signature verification. Without nonces, timestamps, or idempotency keys, a captured legitimate event can be resent after hours.

Our partner-surface audits sample live traffic and secret stores. Teams are often surprised that a retired partner credential still validates on a forgotten staging host that routes to production settlement.