CVE-2026-45830

Vulnerability

A missing authorization check in ChromaDB Python versions 0.4.17 through the latest release (as of the advisory date) allows any authenticated user to read, write, update, or delete data in any tenant's collection. The flaw resides in the SQL query logic within chromadb/db/mixins/sysdb.py (lines 504–520). When a collection UUID is provided, the query skips tenant and database filtering because the code assumes a UUID uniquely identifies a collection. This design decision, documented in an in-code comment, means that the _get_collection() method in chromadb/api/segment.py passes only the UUID without any tenant context, enabling cross-tenant access [1].

Exploitation

An attacker must be an authenticated user of the ChromaDB instance (any privilege level) and know a valid collection UUID. With that UUID, they can directly call API endpoints that accept a collection ID, such as get_collection, add, update, delete, etc. The server will resolve the collection purely by UUID, ignoring the tenant and database scoping that would normally restrict access. No additional authentication or authorization checks are performed [1].

Impact

Successful exploitation allows the attacker to arbitrarily read, write, update, or delete data in any tenant's collection, regardless of which tenant they belong to. This breaks tenant isolation, leading to potential information disclosure, data corruption, or data loss. The attacker gains the same level of access as the legitimate tenant owner for that collection, effectively escalating privileges across tenants [1].

Mitigation

As of the advisory publication date (2026-06-12), no patched version of ChromaDB has been released. Users are advised to restrict network access to the ChromaDB API to trusted clients only, monitor logs for unauthorized access attempts, and consider implementing additional tenant-scoping controls at the network or application layer until a fix is available [1].