KIP-1246 — Deprecate backdoor that allows any client to produce to internal topics

Discussion SecurityBroker

Deprecates the backdoor mechanism that allows any client with clientId __admin_client to produce to internal topics (e.g. __consumer_offsets, __transaction_state) without authorization checks, with removal planned for Kafka 5.0. This bypass poses a security and operational risk: malicious or misconfigured clients can corrupt internal topic state with no differentiation from legitimate admin tooling.

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