There are several security risks associated with webhooks, including server-side request forgery (SSRF), spoofing attacks, replay attacks, and man-in-the-middle (MITM) attacks. To mitigate these risks, it's essential to implement measures such as signing webhooks with strong cryptographic primitives, using HTTPS URLs for encryption, and implementing idempotency and timestamp verification. Additionally, relying solely on IP allow lists is insufficient due to potential sharing of IPs between customers. Implementing secure authentication mechanisms like TLS can also help prevent these attacks, but it requires provisioning client certificates and handling mTLS complexities.