AWS WAF introduces dynamic label interpolation for custom request and response handling

AWS WAF now supports dynamic label interpolation, enabling you to forward WAF classification signals to your origin and embed context in responses with a single rule. Security engineers who previously maintained a separate rule for every signal value can now use ${namespace:} syntax in custom request headers, response headers, and response bodies to forward an entire label namespace at once. For example, one rule with a dynamic variable can forward all IP reputation signals to your application, which can then respond adaptively, such as by enforcing multi-factor authentication (MFA).