CVE-2026-45832: ChromaDB Authorization Bypass via V1 Endpoints

Technical summary

CVE-2026-45832 is an authorization control bypass in ChromaDB (Python) stemming from improper parameter handling in V1 collection-level endpoints. The vulnerability manifests when these endpoints invoke the authorization layer with None values for both tenant and database parameters, causing the authorization checks to fail or be circumvented entirely. This aligns with CWE-551 (Incorrect Initialization with Hard-Coded Network Resource Configuration Data) and CWE-639 (Authorization Bypass Through User-Controlled Key), indicating that authorization decisions are not properly scoped to tenant and database contexts. An authenticated user with valid API credentials can leverage V1 endpoints to bypass role-based or attribute-based access controls.

Business impact

The authorization bypass creates a data confidentiality and integrity risk for ChromaDB deployments, particularly those managing multi-tenant or multi-database environments. Authenticated users could access sensitive vector embeddings, metadata, or collections belonging to other tenants or databases without proper authorization. In environments where ChromaDB stores proprietary or regulated data (e.g., ML model training data, search indices containing PII), unauthorized access could lead to data exfiltration, competitive harm, or regulatory violations. The attack surface is limited to authenticated users, reducing external attack risk, but insider threats or compromised credentials become significantly more dangerous.

Affected systems

The vulnerability impacts all versions of ChromaDB's Python implementation that include V1 collection-level endpoints without a subsequent patch. Organizations running ChromaDB in production should identify their current version and determine whether it uses the affected V1 endpoints. Verify against the official ChromaDB GitHub repository and release notes for patched versions that address tenant and database parameter passing to the authorization layer.

Exploitability

Exploitation requires valid ChromaDB authentication credentials (PR:L in the CVSS vector), meaning the attacker must be a legitimate user or have obtained valid API keys. Once authenticated, no additional interaction or complexity is required—the attack is straightforward network-accessible request manipulation using V1 endpoints. No special knowledge of the target environment is necessary. The CVSS score of 8.8 (HIGH) reflects the combination of network accessibility, low attack complexity, and high impact to confidentiality, integrity, and availability of protected data. The vulnerability does not appear on the CISA KEV catalog, suggesting limited evidence of active exploitation in the wild at publication time.

Remediation

Organizations should prioritize updating ChromaDB to a patched version that correctly passes tenant and database identifiers to the authorization layer. Temporary mitigations may include disabling or restricting access to V1 collection endpoints via API gateway rules, firewall policies, or load balancer configurations if V2 endpoints (if available) provide equivalent functionality. Restrict ChromaDB API access to trusted internal networks and rotate any credentials that may have been used to access the API during the window of vulnerability.

Patch guidance

Check the official ChromaDB releases page and security advisories for version numbers that address this authorization bypass. Apply the patched version after testing in a non-production environment. If ChromaDB is deployed in a containerized or orchestrated environment, update the container image tag and redeploy instances. Verify that the patched version properly passes tenant and database context to authorization checks by reviewing release notes or security advisories from trychroma.

Detection guidance

Monitor ChromaDB API logs for unusual access patterns to collection-level endpoints via the V1 API, particularly requests from users accessing collections outside their expected tenant or database scope. If logging is available, correlate API calls with user identities and look for cross-tenant or cross-database access attempts. Network-based detection could flag suspicious patterns in API request sequences that suggest unauthorized enumeration or data access. Consider implementing temporary audit logging on the authorization layer itself to capture authorization decision details.

Why prioritize this

This vulnerability merits urgent attention due to its high CVSS score (8.8), direct impact on access controls, and potential for data breach. Although exploitation requires authentication, the ease of exploitation once credentials are obtained, combined with the severity of bypass impact (full access to unauthorized data), places it in the top tier for remediation. Organizations with multi-tenant ChromaDB deployments or those storing sensitive data should treat this as critical. The lack of current KEV status does not diminish the risk; it reflects the current state of public exploitation intelligence, not the vulnerability's inherent severity.

Risk score, explained

The CVSS 3.1 score of 8.8 (HIGH) is driven by: (1) Network-accessible attack vector (AV:N), (2) Low attack complexity (AC:L) once authenticated, (3) Requires valid user credentials (PR:L), (4) No user interaction needed (UI:N), (5) Unchanged scope (S:U), and (6) High impact to confidentiality (C:H), integrity (I:H), and availability (A:H) of protected resources. The score appropriately reflects a privilege escalation within the application's trust boundary—an authenticated user gains unauthorized access to data they should not see or modify.

Frequently asked questions