PS Product SecurityKnowledge Base

🔄 Webhooks, OAuth, and SaaS Integration Security

Intro: Integration security is usually where product teams accidentally create broad trust because the external system seems helpful or familiar. This page focuses on the trust decisions hidden inside common SaaS integrations.

What this page includes

  • webhook verification and replay control
  • OAuth scope and lifecycle review
  • partner and SaaS integration risk questions
  • what to document before launch

Webhook review

  • how is payload authenticity verified?
  • what is the replay window?
  • what business action happens if the webhook is accepted?
  • does the receiver log verification result and delivery identity?

OAuth integration review

  • what scopes are requested and why?
  • who approved the scope set?
  • what happens when the token is revoked or expires?
  • can the integration act across tenants or only within one tenant?

Product launch checklist

  • data fields shared with the partner clearly documented;
  • failure and retry behavior reviewed;
  • callback endpoints and secrets rotated without downtime;
  • offboarding path and token revocation defined.

Author attribution: Ivan Piskunov, 2026 - Educational and defensive-engineering use.