Description
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.
Published: 2026-08-30
Score: 2.3 Low
EPSS: < 1% Very Low
KEV: No
Impact: Undisclosed Information Exposure between subscription sessions
Action: Patch Immediately
AI Analysis

Impact

The vulnerability originates from the library's use of a shared process dictionary key, :batch_resolved, to hold resolved subscription data. During synchronous backpressure handling, an outer call can be interrupted by a nested call that reuses the same key, causing the inner resolver to publish the outer subscription's records to its own topic. This results in confidential records being exposed to the wrong subscriber, affecting confidentiality. The weakness is an improper isolation of shared data (CWE‑488).

Affected Systems

ash-project's AshGraphql service is affected. The issue exists in all releases from version 1.4.0 up to but not including 1.11.0. Versions 1.11.0 and later contain the fix that clears, saves, and restores :batch_resolved for every run.

Risk and Exploitability

The CVSS score is 2.3, indicating low severity. The EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog. The likely attack path requires the attacker to influence a subscription resolver that triggers a nested Ash notification within the same process, meaning the threat is confined to the application logic rather than an external network vector.

Generated by OpenCVE AI on August 30, 2026 at 19:22 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade ash_graphql to version 1.11.0 or later, which implements isolation of the batch_resolved key for each run.
  • If an immediate upgrade is not possible, reconfigure notifications to be asynchronous or run resolvers in separate processes to prevent nested synchronous calls from sharing the same process state.
  • Implement validation checks to ensure subscription results are scoped to the correct tenant and actor, and log any mismatches for further investigation.

Generated by OpenCVE AI on August 30, 2026 at 19:22 UTC.

Tracking

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Advisories

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History

Tue, 01 Sep 2026 22:00:00 +0000

Type Values Removed Values Added
Metrics ssvc

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

Sun, 30 Aug 2026 18:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Re-entrant synchronous publish in AshGraphql subscription batcher delivers one subscriber's records to another's topic
First Time appeared Ash-project
Ash-project ash Graphql
Weaknesses CWE-488
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:H/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}

Subscriptions

Ash-project Ash Graphql
cve-icon MITRE

Status: PUBLISHED

Assigner: EEF

Published:

Updated: 2026-09-01T15:37:34.054Z

Reserved: 2026-08-30T17:15:01.277Z

Link: CVE-2026-82367

cve-icon Vulnrichment

Updated: 2026-09-01T15:37:30.535Z

cve-icon NVD

Status : Deferred

Published: 2026-08-30T19:17:29.877

Modified: 2026-09-01T21:15:00.147

Link: CVE-2026-82367

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-31T21:22:38Z

Weaknesses
  • CWE-488

    Exposure of Data Element to Wrong Session