The vulnerability originates from a missing authorization check that allows attackers to use the NotifyOffloadSuccess RPC to inject completed LOCAL_DISK replicas. This flaw permits an unauthenticated actor to choose a client UUID, mount a local disk segment, and attach replicas pointing at attacker-controlled endpoints. The immediate consequence is that a malicious party can serve poisoned disk-tier reads and falsely indicate key existence, potentially compromising data integrity and availability.

The affected product is the Mooncake Store component of kvcache-ai, specifically versions up to and including 0.3.13.post1. The vulnerability applies to any deployment of these releases that exposes the NotifyOffloadSuccess RPC to external or untrusted clients.

The CVSS score of 6.9 classifies the flaw as medium severity. The EPSS score is not available, and the issue is not listed in the CISA KEV catalog. The likely attack vector is network access to the NotifyOffloadSuccess RPC, inferred from the description indicating unauthenticated attackers can invoke the endpoint. Successful exploitation would allow an adversary to manipulate replica metadata and serve malicious data to legitimate clients.