Home/Guides/Request replay safety for webhooks

Request replay safety for webhooks

Replay attacks reuse a previous valid request. Timestamp + signature schemes limit how old a request can be. Reject stale timestamps and verify signatures over the raw body.

Common causes

  • No timestamp in signed payload.
  • Replay window too large.
  • Clock skew between signer and verifier.

How to fix

  • Use Timestamp Validator to compare against tolerance.
  • Reject requests outside the window.
  • Use constant-time signature compare.

Use our tool

Validate timestamp