CVE-2026-78699

rename_tenant returns :ok on a failed rename, enabling cross-tenant access in AshPostgres

Published Aug 30, 2026 CVSS 4.0 · 7.2 High EPSS < 1% KEV · Not listed
Description
Unchecked Return Value vulnerability in ash-project ash_postgres allows a user who can drive a tenant rename to a name that collides with an existing tenant's schema to have their tenant record repointed at that other tenant's live schema, gaining access to its data.

AshPostgres.MultiTenancy.rename_tenant/3 issues the ALTER SCHEMA ... RENAME TO ... with the non-raising Ecto.Adapters.SQL.query/2, discards its {:ok, _} | {:error, _} result, and unconditionally returns :ok. PostgreSQL rejects the rename when the target schema already exists (and on insufficient privilege or lock timeout), but that failure never reaches the caller. The calling manage_tenant update action therefore sees success and commits the tenant row with the new name, which is the schema of a different existing tenant, so subsequent reads and writes for that tenant run against the other tenant's data.

This issue affects ash_postgres: from 0.25.0 before 2.13.0.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Description Unchecked Return Value vulnerability in ash-project ash_postgres allows a user who can drive a tenant rename to a name that collides with an existing tenant's schema to have their tenant record repointed at that other tenant's live schema, gaining access to its data. AshPostgres.MultiTenancy.rename_tenant/3 issues the ALTER SCHEMA ... RENAME TO ... with the non-raising Ecto.Adapters.SQL.query/2, discards its {:ok, _} | {:error, _} result, and unconditionally returns :ok. PostgreSQL rejects the rename when the target schema already exists (and on insufficient privilege or lock timeout), but that failure never reaches the caller. The calling manage_tenant update action therefore sees success and commits the tenant row with the new name, which is the schema of a different existing tenant, so subsequent reads and writes for that tenant run against the other tenant's data. This issue affects ash_postgres: from 0.25.0 before 2.13.0.
Title rename_tenant returns :ok on a failed rename, enabling cross-tenant access in AshPostgres
First Time appeared Ash-project
Ash-project ash Postgres
Weaknesses CWE-252
CPEs cpe:2.3:a:ash-project:ash_postgres:*:*:*:*:*:*:*:*
Vendors & Products Ash-project
Ash-project ash Postgres
References
Metrics cvssV4_0

{'score': 7.2, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
EEF
Published
Updated
Sep 1, 2026, 12:30 PM
Reserved
Aug 30, 2026, 6:00 AM
Status
Deferred
Published
Aug 30, 2026, 4:16 PM
Modified
Sep 1, 2026, 9:15 PM