rename_tenant returns :ok on a failed rename, enabling cross-tenant access in AshPostgres (CVE-2026-78699) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-78699

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

Answer in brief

CVE-2026-78699 records a Unknown severity vulnerability in rename_tenant returns :ok on a failed rename, enabling cross-tenant access in AshPostgres. The current sources do not mark it as known exploited. The current feed maps ash-project/ash_postgres (generic), ash-project/ash_postgres (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 30, 2026Updated Aug 30, 2026Source checked Aug 30, 2026First seen by HOL Aug 30, 2026Material review Aug 30, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps ash-project/ash_postgres (generic), ash-project/ash_postgres (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
ash-project/ash_postgresgeneric	>=0.25.0 <2.13.0	2.13.0
ash-project/ash_postgresgeneric	>=03510dae24020e302558ef947be7ea874a9ce756 <8544ab15fe45784553c2d2da8ee1a388eee0174b	8544ab15fe45784553c2d2da8ee1a388eee0174b

Recommended response

Check inventory. Check lockfiles and deployed manifests for ash-project/ash_postgres, ash-project/ash_postgres.
Review the reported fix. Update ash-project/ash_postgres to 2.13.0; ash-project/ash_postgres to 8544ab15fe45784553c2d2da8ee1a388eee0174b if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 30, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 30, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 30, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.