A vulnerability in the multi‑tenant plugin allows an authenticated user who is restricted to a single tenant to create a new record in a different tenant. The issue does not enable the attacker to read or edit existing documents, but it permits the creation of arbitrary data in the target tenant. This creates a breach of separation between tenants, potentially leaking proprietary content or corrupting the target tenant’s data integrity. The weakness corresponds to improper access control (CWE‑863).

The flaw affects payloadcms users running @payloadcms/plugin‑multi‑tenant prior to version 3.90.0 and canary releases prior to 4.0.0‑canary.34, as well as the core payloadcms payload package in the same version range. Both the plugin and core components are impacted when a tenant‑enabled collection exists.

The CVSS score of 5.3 indicates a medium severity condition. Exploitation requires a legitimate authenticated session with limited tenant permissions, and the attacker must have at least one tenant‑enabled collection. The EPSS score is not available, and the vulnerability is not listed in CISA’s KEV catalog. Because the creator role must be authenticated, the attack vector is limited to internal or compromised legitimate users rather than external remote attackers. The lack of a read or edit bypass limits the scope of damage, but the ability to add records still violates tenant isolation and can be abused for data pollution or other malicious activity.