CVE-2026-81318
Distinct-query aggregate drops the tenant schema prefix, leaking across tenants in AshSql
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
2.1
Distinct-query aggregate drops the tenant schema prefix, leaking across tenants in AshSql
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.
- Record
CVE-2026-81318- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-863
- Updated
- 2026-11-02
EUVDEUVD-2026-68189
2.1
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.
- Record
EUVD-2026-68189- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
NVD
2.1
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.
- Record
CVE-2026-81318- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-863
- Updated
- 2026-11-02
OSV
2.1
Distinct-query aggregate drops the tenant schema prefix, leaking across tenants in AshSql
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.
- Record
CVE-2026-81318- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-863
- Updated
- 2026-11-02
OSVEEF-CVE-2026-81318
2.1
Distinct-query aggregate drops the tenant schema prefix, leaking across tenants in AshSql
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, 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.
Configurations
An application must use AshPostgres schema-based (strategy(:context)) multitenancy and compute an aggregate over a distinct query (for example an aggregate whose query filters across a to-many relationship).
- Record
EEF-CVE-2026-81318- CVSS 4.0
- 2.1 Low
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-863
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
ash_sqlHex |
0.1.0 up to 0.7.1, plus listed versions 0.1.1-rc.00.1.1-rc.10.1.1-rc.100.1.1-rc.110.1.1-rc.12 Show 45 moreShow less0.1.1-rc.130.1.1-rc.140.1.1-rc.150.1.1-rc.160.1.1-rc.170.1.1-rc.180.1.1-rc.190.1.1-rc.20.1.1-rc.200.1.1-rc.30.1.1-rc.40.1.1-rc.50.1.1-rc.60.1.1-rc.70.1.1-rc.80.1.1-rc.90.1.20.1.30.2.00.2.10.2.100.2.110.2.120.2.130.2.140.2.150.2.160.2.170.2.180.2.190.2.20.2.200.2.210.2.220.2.230.2.240.2.250.2.260.2.270.2.280.2.290.2.30.2.300.2.310.2.32 |
0.7.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-81318 is a low vulnerability (CVSS 2.1) in Ash-project Ash Sql, published August 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. Fixed in ash_sql 0.7.1.
References
Left out here: 107 versions. The JSON record has them.