GHSA-v73x-hx65-6pf4: Gitea: Unauthorized Access to Labels of Private Organizations

Summary Gitea 1.26.2 does not properly enforce organization visibility restrictions on organization label read endpoints. A user without access to a private organization can retrieve labels belonging to that organization through the Organization Labels API. As a result, label metadata intended to be restricted to organization members may be disclosed. The issue is limited to unauthorized read access. No unauthorized modification of labels was observed. Details The following endpoints are affected: - GET /api/v1/orgs/{org}/labels - GET /api/v1/orgs/{org}/labels/{id} During testing, a private organization was created and a label was added to that organization. Access to the organization itself was correctly restricted. A user without membership in the organization received a 404 Not Found response when requesting organization information. However, the same user was still able to retrieve organization labels through the endpoints listed above. For comparison, other organization-scoped endpoints such as: - GET /api/v1/orgs/{org}/teams - GET /api/v1/orgs/{org}/hooks - GET /api/v1/orgs/{org}/actions/secrets correctly denied access to unauthorized users. The label endpoints returned the full Label object, including fields such as: - id - name - description - color - url Write operations were tested separately and remained protected by authorization checks. PoC Setup Create a private organization: POST /api/v1/orgs Authorization: token <owner_token> { "username": "target-org", "visibility": "private" } Create a label: POST /api/v1/orgs/target-org/labels Authorization: token <owner_token> { "name": "internal-label", "color": "#aabbcc", "description": "private organization label" } Verify that the organization is not accessible to a non-member: GET /api/v1/orgs/target-org Authorization: token <non_member_token> Response: HTTP/1.1 404 Not Found Retrieve all labels Request: GET /api/v1/orgs/target-org/labels Authorization: token <non_member_token>