Executive brief
Label Studio is a data labeling and annotation platform that manages cloud storage access for tasks and projects. An attacker can bypass multi-tenant isolation by creating a separate organization and accessing other tenants' cloud storage objects without proper authorization, exposing sensitive files stored in shared buckets.
Technical details
Label Studio fails to apply organization filters when resolving storage URIs in proxy_api.py endpoints that handle task and project storage access. The vulnerability is a multi-tenant authorization bypass (CWE-639/CWE-284) affecting storage presigning and streaming operations. An attacker authenticated to one organization can craft requests with arbitrary storage URIs to access cloud storage objects belonging to other organizations. No special privileges are required beyond creating a separate organization account. The attack is network-reachable and does not require additional user interaction.
Affected products
- HumanSignal Label Studio 1.23.0 and likely prior versions
Timeline
- 2026-09-03: disclosed