Perses is an open-source dashboard and visualization project for observability data. Prior to 0.54.0-beta.3, an authenticated user with viewer access to one project can supply another project through the project query parameter on project-scoped list endpoints, including /api/v1/projects/{project}/dashboards and /api/v1/datasources. The request-controlled project value is used to select dashboards, datasources, and variables without enforcing the caller's authorization for that selected project, which breaks project-level tenant isolation and exposes complete resource specifications belonging to other projects. This issue is fixed in version 0.54.0-beta.3.