GHSA-f48p-c9v4-h7xv: Echo: BodyDump captures request and response bodies without size limits in v4

Echo v4’s opt-in BodyDump middleware read complete request bodies into memory and retained complete response bodies without a capture limit. A client able to submit large requests to a route using BodyDump could cause large allocations before the application handler ran. Large responses, including responses whose size can be influenced by a client, also caused an additional unbounded capture allocation.

Repeated or concurrent requests can exhaust process memory and cause denial of service. BodyDump is not enabled by default. Deployments with effective request limits may reduce the request-side exposure; response capture requires separate consideration.