CVE-2026-81643

Broken access control in AshGraphql subscription batcher applies authorization suppression to only the first notification

Published Aug 30, 2026 CVSS 4.0 · 2.3 Low EPSS < 1% KEV · Not listed
Description
Incorrect Authorization vulnerability in ash-project ash_graphql delivers GraphQL subscription payloads for records a subscriber is not authorized to see.

In AshGraphql.Subscription.Batcher, do_send/5 resolves the first notification of a batch and filters it with should_send?/1, which drops results whose errors are coded forbidden or not_found 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.publish_subscription/2, and the not is_nil(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 should_send?/1 to the whole batch.

This issue affects ash_graphql: from 1.4.0 before 1.11.0.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Incorrect Authorization vulnerability in ash-project ash_graphql delivers GraphQL subscription payloads for records a subscriber is not authorized to see. In AshGraphql.Subscription.Batcher, do_send/5 resolves the first notification of a batch and filters it with should_send?/1, which drops results whose errors are coded forbidden or not_found 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.publish_subscription/2, and the not is_nil(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 should_send?/1 to the whole batch. This issue affects ash_graphql: from 1.4.0 before 1.11.0.
Title Broken access control in AshGraphql subscription batcher applies authorization suppression to only the first notification
First Time appeared Ash-project
Ash-project ash Graphql
Weaknesses CWE-863
CPEs cpe:2.3:a:ash-project:ash_graphql:*:*:*:*:*:*:*:*
Vendors & Products Ash-project
Ash-project ash Graphql
References
Metrics cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
EEF
Published
Updated
Aug 31, 2026, 3:01 PM
Reserved
Aug 30, 2026, 4:45 AM
Status
Deferred
Published
Aug 30, 2026, 7:17 PM
Modified
Sep 1, 2026, 9:15 PM