---
id: CVE-2026-81318
title: >-
  Incorrect Authorization vulnerability in ash-project ash_sql allows a caller
  in a schema-based multitenant application to receive aggregate values computed
  from another tenant's rows.


  When an aggregate is computed over a distinct query,…
summary: >-
  Incorrect Authorization vulnerability in ash-project ash_sql allows a caller
  in a schema-based multitenant application to receive aggregate values computed
  from another tenant's rows.


  When an aggregate is computed over a distinct query,…
severity: none
cwe:
  - CWE-863
published: '2026-08-30'
updated: '2026-08-30'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-81318'
references:
  - url: 'https://cna.erlef.org/cves/CVE-2026-81318.html'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/ash-project/ash_sql/commit/3d95478cc9e1d5bfaf6144fe9b9793f29e5ab889
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: >-
      https://github.com/ash-project/ash_sql/security/advisories/GHSA-ww8j-58rc-f8h3
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
  - url: 'https://osv.dev/vulnerability/EEF-CVE-2026-81318'
    label: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
tags:
  - nvd
ingestedAt: '2026-08-30T18:56:19.087Z'
epss: 0.00171
epssPercentile: 0.05679
---

## Overview

Incorrect Authorization vulnerability in ash-project ash_sql allows a caller in a schema-based multitenant application to receive aggregate values computed from another tenant's rows.

When an aggregate is computed over a distinct query, AshSql.AggregateQuery.add_single_aggs/5 rebuilds the outer query from query.from.source alone, which is only the {table, schema} tuple and does not carry query.prefix or query.from.prefix. For strategy(:context) multitenancy those hold the tenant schema, so the rebuilt outer query reads the repo's default schema while the inner correlated subquery still reads the tenant schema, and the two are joined only on primary key. The aggregate, and any relationship join added off the prefix-less binding, is then computed against the wrong tenant's rows. The neighbouring limit and exists branches instead wrap the query with subquery/1, which preserves the prefix.

This issue affects ash_sql: from 0.1.0 before 0.7.1.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.