CVE-2026-27835: wger IDOR Vulnerability

MODERATE
Advisory Identifier: GHSA-xf68-8hjw-7mpm
CVSS 4.3
CWE-639
Published
Advisory Summary

CVE-2026-27835 is a MODERATE (CVSS 4.3) idor vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affecting wger libraries in the PyPI ecosystem. The issue involves idor in repetitionsconfig and maxrepetitionsconfig api leak other users' workout data. Remediation is available in the latest vendor maintenance releases.

CVE-2026-27835 at a Glance

CVE Identifier CVE-2026-27835
GHSA Identifier GHSA-xf68-8hjw-7mpm
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-639: Authorization Bypass Through User-Controlled Key
Affected Product wger
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-27835

To remediate this vulnerability, upgrade all affected wger dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

wger fixed: Latest secure release
pip install wger>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show wger

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-27835, inspect your installed packages using pip:

pip show wger

Analyze the terminal output to locate any version of wger in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The pip show wger command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key, where the system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. In wger, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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

CVE-2026-27835 Affected wger Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
wger
PyPI
≤ 2.1

References

Frequently Asked Questions

What is CVE-2026-27835?
CVE-2026-27835 is a security vulnerability in wger involving IDOR in RepetitionsConfig and MaxRepetitionsConfig API leak other users' workout data under CWE-639: Authorization Bypass Through User-Controlled Key.
Which wger versions are affected?
Affected versions include releases prior to current release patches across affected packages: wger.
What version fixes CVE-2026-27835?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is wger affected?
Yes, wger is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-27835?
CVE-2026-27835 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-27835?
CVE-2026-27835 is classified under CWE-639: Authorization Bypass Through User-Controlled Key (The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.).
How can I check PyPI dependencies for CVE-2026-27835?
Run the dependency tree command: 'pip show wger'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-xf68-8hjw-7mpm",
  "modified" : "2026-04-15T20:42:17Z",
  "published" : "2026-02-26T22:13:13Z",
  "aliases" : [ "CVE-2026-27835" ],
  "summary" : "wger: IDOR in RepetitionsConfig and MaxRepetitionsConfig API leak other users' workout data",
  "details" : "### Summary\n\n`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.\n\n### Details\n\n`wger/manager/api/views.py:499` and `:518`:\n\n```python\n# VULNERABLE\nclass RepetitionsConfigViewSet(viewsets.ModelViewSet):\n    def get_queryset(self):\n        return RepetitionsConfig.objects.all()\n\nclass MaxRepetitionsConfigViewSet(viewsets.ModelViewSet):\n    def get_queryset(self):\n        return MaxRepetitionsConfig.objects.all()\n```\n\nEvery sibling viewset in the same file correctly filters by user. For example, `WeightConfigViewSet` at line 459:\n\n```python\n# CORRECT — how it should work\ndef get_queryset(self):\n    return WeightConfig.objects.filter(\n        slot_entry__slot__day__routine__user=self.request.user\n    )\n```\n\nThe same user filter is present on `SetsConfig`, `RestConfig`, `RiRConfig`, and their Max variants — only `RepetitionsConfig` and `MaxRepetitionsConfig` are missing it.\n\n### PoC\n\n```python\nimport requests\n\nBASE = \"http://localhost\"\nheaders = {\"Authorization\": \"Token YOUR_TOKEN\"}  # any registered user\n\nr = requests.get(f\"{BASE}/api/v2/repetitions-config/\", headers=headers)\nprint(r.json())  # returns ALL users' repetition configs, not just your own\n\nr = requests.get(f\"{BASE}/api/v2/max-repetitions-config/\", headers=headers)\nprint(r.json())  # same — all users' max repetition configs\n```\n\nRegistration is open by default. Sequential IDs allow full enumeration.\n\n### Impact\n\nAny 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.\n\n**Fix**: Add the same user filter used by every other config viewset:\n```python\ndef get_queryset(self):\n    return RepetitionsConfig.objects.filter(\n        slot_entry__slot__day__routine__user=self.request.user\n    )\n```",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "wger"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/wger-project/wger/security/advisories/GHSA-xf68-8hjw-7mpm"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-27835"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/wger-project/wger/commit/1fda5690b35706bb137850c8a084ec6a13317b64"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/wger-project/wger"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-26T22:13:13Z",
    "nvd_published_at" : "2026-02-26T22:20:49Z"
  }
}