CVE-2026-92782 in Chroma
Summary
by MITRE • 09/16/2026
Chroma through 1.5.9 fails to validate tenant and database segments when resolving collections, allowing authenticated attackers to access collections from other tenants by knowing the collection identifier. Attackers can read, modify, and update records in foreign collections by issuing requests under their own tenant path, bypassing authorization checks.
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Analysis
by VulDB Data Team • 09/16/2026
The vulnerability identified in Chroma versions through 1.5.9 represents a critical failure in multi-tenant isolation mechanisms within the vector database architecture. This flaw stems from an insufficient validation of tenant and database segments during the resolution process for collection identifiers. In a properly secured multi-tenancy model, each logical tenant should operate within an isolated namespace where access to resources is strictly gated by identity verification and authorization checks tied to that specific tenant context. However, in this affected implementation, the system fails to enforce these boundaries when resolving collections based on their unique identifiers. This architectural oversight allows authenticated users to bypass intended isolation controls simply by manipulating or knowing the identifier of a collection belonging to another tenant.
From a technical perspective, the core issue lies in how the application maps incoming requests to internal data structures. When an authenticated user issues a request targeting a specific collection ID, the backend logic retrieves and processes that resource without verifying whether the requesting user's assigned tenant context matches the owner or authorized scope of that collection. Consequently, if an attacker knows the identifier of a target collection, they can construct API calls using their own valid authentication credentials but pointing to foreign resources. The system accepts these requests as legitimate because it trusts the provided ID over the contextual security constraints associated with the user's session. This effectively neutralizes the authorization layer that is supposed to prevent cross-tenant data access.
The operational impact of this vulnerability is severe, particularly for organizations relying on Chroma for sensitive machine learning workloads or proprietary data storage. Attackers who gain authenticated access can read confidential embeddings and metadata stored in other tenants' collections, leading to significant data exfiltration risks. Furthermore, the ability to modify and update records means that attackers can inject malicious vectors, alter existing data integrity, or delete critical information. This not only compromises confidentiality but also undermines the integrity and availability of services for legitimate users sharing the same infrastructure. In scenarios where Chroma is used as a backend for retrieval-augmented generation systems, such tampering could lead to poisoned AI outputs or compromised decision-making processes downstream.
This vulnerability aligns with CWE-284 Improper Access Control, specifically reflecting failures in enforcing user isolation and boundary enforcement between different security contexts. It also maps closely to MITRE ATT&CK techniques related to Lateral Movement and Data Exfiltration within cloud environments, as the attacker leverages valid credentials to access resources outside their designated scope without requiring privilege escalation or credential theft beyond initial authentication. The lack of strict validation on resource identifiers is a common pitfall in API-driven applications where trust is placed too heavily on client-supplied data rather than server-side context verification.
To mitigate this risk, immediate action should be taken by upgrading to a patched version of Chroma that addresses the tenant isolation logic. In environments where an upgrade is not immediately feasible, administrators can implement network-level controls such as firewalls or API gateways to restrict access based on IP reputation if possible, though this is less effective against authenticated attacks. More critically, application-layer mitigations should be reviewed; developers must ensure that all resource resolution endpoints enforce strict checks comparing the tenant ID from the authentication token against the ownership metadata of the requested collection. Implementing robust logging and monitoring for unusual cross-tenant access patterns can also aid in early detection of exploitation attempts while permanent fixes are deployed. Regular security audits focusing on multi-tenancy implementations are essential to prevent similar logical flaws in future updates or custom integrations.