CVE-2026-27835

RepetitionsConfigViewSet and MaxRepetitionsConfigViewSet return all users' repetition config data because their get_queryset() calls .all() instead of filtering by the authenticated user. Any registered user can enumerate every other user's workout structure.

Details

wger/manager/api/views.py:499 and :518:

# VULNERABLE
class RepetitionsConfigViewSet(viewsets.ModelViewSet):
    def get_queryset(self):
        return RepetitionsConfig.objects.all()

class MaxRepetitionsConfigViewSet(viewsets.ModelViewSet):
    def get_queryset(self):
        return MaxRepetitionsConfig.objects.all()

Every sibling viewset in the same file correctly filters by user. For example, WeightConfigViewSet at line 459:

# CORRECT, how it should work
def get_queryset(self):
    return WeightConfig.objects.filter(
        slot_entry__slot__day__routine__user=self.request.user
    )

The same user filter is present on SetsConfig, RestConfig, RiRConfig, and their Max variants, only RepetitionsConfig and MaxRepetitionsConfig are missing it.

PoC

import requests

BASE = "http://localhost"
headers = {"Authorization": "Token YOUR_TOKEN"}  # any registered user

r = requests.get(f"{BASE}/api/v2/repetitions-config/", headers=headers)
print(r.json())  # returns ALL users' repetition configs, not just your own

r = requests.get(f"{BASE}/api/v2/max-repetitions-config/", headers=headers)
print(r.json())  # same, all users' max repetition configs

Registration is open by default. Sequential IDs allow full enumeration.

Any authenticated user can read other users' repetition and max-repetitions configs, exposing workout structure (slot entry IDs, iteration values, operations, step counts, repeat flags, requirements JSON). This is a broken object-level authorization (BOLA/IDOR) vulnerability, the same class of issue as OWASP API1.

Fix: Add the same user filter used by every other config viewset:

def get_queryset(self):
    return RepetitionsConfig.objects.filter(
        slot_entry__slot__day__routine__user=self.request.user
    )

CVE-2026-27835 has a CVSS score of 4.3 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.

Kodem intelligence

1. What is CVE-2026-27835? CVE-2026-27835 is a medium-severity security vulnerability in wger (pip), affecting versions <= 2.1. No fixed version is listed yet.
2. How severe is CVE-2026-27835? CVE-2026-27835 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of wger are affected by CVE-2026-27835? wger (pip) versions <= 2.1 is affected.
4. Is there a fix for CVE-2026-27835? No fixed version is listed for CVE-2026-27835 yet. Monitor the advisory for updates and apply mitigations in the interim.
5. Is CVE-2026-27835 exploitable, and should I be worried? Whether CVE-2026-27835 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-27835 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.