CVE-2026-45831

Vulnerability

The SimpleRBACAuthorizationProvider in ChromaDB versions 0.5.0 through 1.5.9 evaluates whether a user holds a given action (e.g., read, write) but never checks the tenant, database, or collection scope of that permission [1]. The authorization logic in chromadb/auth/simple_rbac_authz/__init__.py builds a mapping of user_id -> set(actions) and only verifies that the requested action exists in that set [1]. This allows any user with a valid permission to perform that action across all tenants, databases, and collections, bypassing intended resource boundaries [1].

Exploitation

An attacker with valid credentials and a role that grants even a single permission (e.g., read on any resource) can access or modify data belonging to any tenant, database, or collection [1]. No additional privileges, network position beyond normal API access, or user interaction is required. The attacker simply issues authenticated API requests for resources outside their intended scope [1].

Impact

Successful exploitation permits unauthorized read and write access to all ChromaDB data across tenants [1]. An attacker can read sensitive vectors, documents, or metadata from any tenant (confidentiality breach), modify or delete data in any tenant (integrity compromise), and potentially disrupt service availability. The CVSS v4.0 score is 8.9, with high impacts on confidentiality, integrity, and availability for both the vulnerable system and subsequent systems [1].

Mitigation

As of the advisory publication date (2026-06-12), no patch has been released; the latest affected version is 1.5.9 [1]. ChromaDB has acknowledged the vulnerability and indicated a fix will be included in a future release [1]. Until a patched version is available, administrators should restrict network access to the API, monitor for anomalous cross-tenant requests, and avoid relying on the SimpleRBACAuthorizationProvider for multi-tenant isolation. This CVE is not listed on CISA's Known Exploited Vulnerabilities catalog.