A critical vulnerability in ash_postgres allows an authenticated user to gain unauthorized access to data belonging to other tenants through a tenant rename collision.

This is an unchecked return value vulnerability (CWE-252) occurring in the AshPostgres.MultiTenancy.rename_tenant function, where database errors are ignored, allowing an authenticated user to manipulate schema associations.

Successful exploitation allows an authenticated user to bypass tenant isolation boundaries, resulting in unauthorized access to sensitive data belonging to other tenants. With a CVSS score of 7.2, this vulnerability represents a significant risk to data confidentiality and integrity, potentially leading to severe regulatory compliance issues and loss of customer trust.

Immediate Action: Upgrade ash_postgres to version 2.13.0 or later immediately to incorporate the necessary error handling for tenant rename operations.

Proactive Monitoring: Review application and database logs for failed or unusual tenant rename operations that might indicate an attempt to trigger schema collisions.

Compensating Controls: Restrict access to tenant management functions to highly privileged users only, and implement application-level validation to prevent naming collisions before database operations occur.

Public Exploit Available: Unknown

The risk posed by this vulnerability is high due to the potential for cross-tenant data exposure. Security teams should prioritize updating the ash_postgres package to the patched version 2.13.0 across all environments to ensure proper validation of database state changes and maintain strict tenant isolation.