EEF-CVE-2026-82367

## Summary

Exposure of Data Element to Wrong Session vulnerability in ash-project ash\_graphql can deliver one subscription's resolved records to a different subscriber's topic.

AshGraphql.Subscription.Batcher.do\_send/5 reads the resolved batch from the process dictionary via Process.get(:batch\_resolved) and then unconditionally deletes it. That is sound only inside a task the library owns. On the :backpressure\_sync and :noproc fallbacks do\_send/5 runs inline in the publishing caller's process, so if a resolver inside an outer do\_send/5 triggers another synchronous Ash notification, the inner call finds the outer run's value still under :batch\_resolved, adopts it as its own result, and publishes it to the inner topic, a different subscription document with a different actor and tenant. It then deletes the key, so the outer run publishes nothing. The key is not namespaced by run, so records cannot be told apart. The fix saves, clears, and restores :batch\_resolved around each run.

This issue affects ash\_graphql: from 1.4.0 before 1.11.0.

## Configuration

The application uses ash\_graphql subscriptions where a subscription resolver's execution can itself emit an Ash notification, and delivery takes the synchronous :backpressure\_sync or :noproc (missing-batcher) path rather than a library-owned task.