CVE-2026-76073: Authorization Bypass Through User-Controlled Key in HumanSignal label-studio

Label Studio's AnnotationAPI endpoint in label_studio/tasks/api.py uses a queryset that returns all Annotation objects without scoping to the requester's organization. The permission checks only verify that the user is authenticated but do not enforce object-level organization restrictions. Since annotation IDs are sequential integers, an authenticated user can enumerate these IDs to read, modify, or delete annotations from other organizations on the same instance. This lack of proper scoping applies to both the AnnotationAPI and AnnotationConvertAPI endpoints.

Authenticated users can bypass authorization controls to access and manipulate annotations belonging to other organizations within the same Label Studio instance. This can lead to unauthorized data disclosure, modification, and deletion across organizational boundaries, violating data confidentiality and integrity.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to the affected endpoints or implement custom access controls to enforce organization-level scoping on annotation queries.