CVE-2026-104867: Immich calendar heatmap endpoint discloses cross-user activity through broken access control

Immich is a high-performance self-hosted photo and video management solution. From 3.0.0 until 3.2.0, the GET /api/admin/users/{id}/calendar-heatmap route in server/src/controllers/user-admin.controller.ts uses the ordinary Permission.UserRead permission without an admin-route requirement, and UserAdminService.getCalendarHeatmap in server/src/services/user-admin.service.ts does not compare the authenticated user with the requested user identifier or perform a separate access check. Any authenticated non-admin user can therefore request another account's upload or capture-date activity heatmap for an arbitrary date range. AssetRepository.getCalendarHeatmap in server/src/repositories/asset.repository.ts filters by owner, date, and deletion state but not visibility, so the returned daily counts and total count include archived and locked assets. The route exposes counts and activity dates but does not return asset metadata or content, and it does not affect integrity or availability. This issue is fixed in version 3.2.0.