Apache Polaris allows an authenticated principal with permission to create or update Iceberg table properties to set FileIO client settings such as s3.endpoint in table metadata. In versions < 1.8.0, when Polaris performs server-side Iceberg operations, including commits and purges, it may use those settings to construct its (server-side) FileIO client. If the catalog storage configuration does not override the endpoint, Polaris can send storage requests to a host chosen by the table writer, using credentials scoped to the operation. This can redirect server-side storage traffic and expose request authentication material to the chosen endpoint. Deployments are affected when table writers are not trusted to configure server-side storage endpoints.