CVE-2026-27835 is a medium-severity (CVSS 4.3) CWE-639 vulnerability in wger. No vendor fix is recorded yet; mitigation options are listed below.
wger: IDOR in RepetitionsConfig and MaxRepetitionsConfig API leak other users' workout data
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-27835.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-27835 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
wgerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
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.
Impact
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
)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | wger | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wger, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of wger has shipped for CVE-2026-27835 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-27835 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-27835. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-27835 in your dependencies?
O3 Security finds CVE-2026-27835 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.