ZenML CVE-2026-11976: Cross-Tenant Stack Enumeration via Missing RBAC in get_deployed_stack

Vulnerability Overview Vulnerability Name: Missing Authorization in get_deployed_stack Endpoint Allows Cross-Tenant Stack Enumeration via Server-Side Client Bypass in zenml-io/zenml CVE Number: CVE-2026-11976 Vulnerability Type: CWE-862: Missing Authorization Severity: Medium (5) Affected Version: 0.94.2 Fix Status: Fixed Discovered By: dukesp69 Fixed By: Stefan Nica Description: This vulnerability exists in ZenML's endpoint, which lacks an RBAC (Role-Based Access Control) authorization check. An attacker can exploit this vulnerability to enumerate all deployed stacks, including those belonging to other users and tenants, thereby obtaining stack component details and service connector information. Impact Scope Infrastructure Topology: Cloud providers, regions, stack component types Service Connector Details: Connector type, authentication methods, resource types Stack Ownership: User IDs of stack owners in other tenants Deployment Metadata: Labels, creation dates, deployment providers In multi-tenant ZenML Pro/Cloud deployments, this vulnerability can lead to cross-tenant reconnaissance, facilitating further attacks (e.g., identifying high-value targets through service connector validation endpoints). Remediation 1. Layer 1 — Missing endpoint-level RBAC (N-1 of N pattern): - In the file, the endpoint lacks a call. - Fix: Add a call to the endpoint. 2. Layer 2 — Server-side Client() bypasses RBAC entirely: - The method in uses to resolve to on the server side, bypassing the RBAC enforcement layer. - Fix: Add RBAC filtering to the method. POC Code References CWE-862: Missing Authorization OWASP Broken Access Control Locations Impact This vulnerability allows any authenticated user (even non-administrators) to enumerate all deployed cloud stacks, including those belonging to other users and tenants, thereby exposing the following information: Infrastructure Topology: Cloud providers, regions, stack component types Service Connector Details: Connector type, authentication methods, resource types Stack Ownership: User IDs of stack owners in other tenants Deployment Metadata: Labels, creation dates, deployment providers In multi-tenant ZenML Pro/Cloud deployments, this vulnerability can lead to cross-tenant reconnaissance, facilitating further attacks (e.g., identifying high-value targets through service connector validation endpoints). Remediation 1. Layer 1 — Missing endpoint-level RBAC (N-1 of N pattern): - In the file, the endpoint lacks a call. - Fix: Add a call to the endpoint. 2. Layer 2 — Server-side Client() bypasses RBAC entirely: - The method in uses to resolve to on the server side, bypassing the RBAC enforcement layer. - Fix: Add RBAC filtering to the method. References CWE-862: Missing Authorization OWASP Broken Access Control Locations Impact This vulnerability allows any authenticated user (even non-administrators) to enumerate all deployed cloud stacks, including those belonging to other users and tenants, thereby exposing the following information: Infrastructure Topology: Cloud providers, regions, stack component types Service Connector Details: Connector type, authentication methods, resource types Stack Ownership: User IDs of stack owners in other tenants Deployment Metadata: Labels, creation dates, deployment providers In multi-tenant ZenML Pro/Cloud deployments, this vulnerability can lead to cross-tenant reconnaissance, facilitating further attacks (e.g., identifying high-value targets through service connector validation endpoints). Remediation 1. Layer 1 — Missing endpoint-level RBAC (N-1 of N pattern): - In the file, the endpoint lacks a call. - Fix: Add a call to the endpoint. 2. Layer 2 — Server-side Client() bypasses RBAC entirely: - The method in uses to resolve to on the server side, bypassing the RBAC enforcement layer. - Fix: Add RBAC filtering to the method. References CWE-862: Missing Authorization OWASP Broken Access Control Locations Impact This vulnerability allows any authenticated user (even non-administrators) to enumerate all deployed cloud stacks, including those belonging to other users and tenants, thereby exposing the following information: Infrastructure Topology: Cloud providers, regions, stack component types Service Connector Details: Connector type, authentication methods, resource types Stack Ownership: User IDs of stack owners in other tenants Deployment Metadata: Labels, creation dates, deployment providers In multi-tenant ZenML Pro/Cloud deployments, this vulnerability can lead to cross-tenant reconnaissance, facilitating further attacks (e.g., identifying high-value targets through service connector validation endpoints). Remediation 1. Layer 1 — Missing endpoint-level RBAC (N-1 of N pattern): - In the file, the endpoint lacks a call. - Fix: Add a call to the endpoint. 2. Layer 2 — Server-side Client() bypasses RBAC entirely: - The method in uses to resolve to on the server side, bypassing the RBAC enforcement layer. - Fix: Add RBAC filtering to the method.

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ZenML CVE-2026-11976: Cross-Tenant Stack Enumeration via Missing RBAC in get_deployed_stack