Incorrect Authorization vulnerability in ash-project ashgraphql delivers GraphQL subscription payloads for records a subscriber is not authorized to see.
In AshGraphql.Subscription.Batcher, dosend/5 resolves the first notification of a batch and filters it with shouldsend?/1, which drops results whose errors are coded forbidden or notfound or carry no code, precisely so that unauthorized results are not disclosed. The remaining notifications in the batch are read from the process dictionary, re-run through the pipeline, and appended to the outgoing results without that filter. They reach pubsub.publishsubscription/2, and the not isnil(record) guard drops only nil records, not error-carrying results. Any two qualifying notifications arriving within the default one-second batch interval suffice, and batching is the default path. The fix applies shouldsend?/1 to the whole batch.
This issue affects ashgraphql: from 1.4.0 before 1.11.0.