CVE-2026-81643: CWE-863 Incorrect Authorization in ash-project ash_graphql

The vulnerability arises in AshGraphql.Subscription.Batcher where the first notification in a batch is filtered correctly using should_send?/1 to exclude unauthorized results. However, subsequent notifications in the batch bypass this filter and are sent without proper authorization checks. This leads to unauthorized data being delivered to subscribers. The flaw exists in ash_graphql versions >=1.4.0 and <1.11.0. The fix involves applying the should_send?/1 filter to the entire batch of notifications.

Subscribers to GraphQL subscriptions may receive data records they are not authorized to access, potentially exposing sensitive information. The CVSS 4.0 base score is 2.3, indicating a low severity impact with network attack vector, low complexity, and partial attack and privilege requirements. There are no known exploits in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The described fix involves applying the authorization filter to all batched notifications. Until an official fix is released, users should be cautious with subscription data exposure and consider restricting access or disabling subscriptions if feasible.