wger: cross-tenant admin notes/contracts leak via gym=None bypass (5 views)

{
  "id": "d2d699ddca404db112f233b966e173fb37249cd80c8b467a8eb06136582a04ef",
  "url": "https://osv.dev/vulnerability/PYSEC-2026-4313",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "wger: cross-tenant admin notes/contracts leak via gym=None bypass (5 views)",
    "summary": "### Summary Five gym management views in wger apply a flawed gym-scope guard (`gym_a != gym_b`) that silently passes when both operands are `None`. A trainer with `gym.gym_trainer` and `gym.add_adminusernote` permissions and no gym assignment (`gym=None`) can read private admin notes, uploaded documents, gym contracts, user configuration, and user permission data for **any other unaffiliated user** on the instance. The subsequent querysets filter only on the attacker-supplied `member_id` with no secondary gym-scoped validation, so all records are disclosed. ### Details **Files**: `wger/gym/views/user.py`, `wger/gym/views/admin_notes.py`, `wger/gym/views/document.py`, `wger/gym/views/contract.py`, `wger/gym/views/user_config.py` The same flawed comparison pattern appears across at least five views: ```python # VULNERABLE - applied in admin_notes_list, documents_list, contracts_list, # user_config, and gym_permissions_user_edit if request.user.userprofile.gym != user.userprofile.gym: return HttpResponseForbidden() # After the guard (admin notes example): notes = AdminUserNote.objects.filter(member=member) # only filtered by member_id ``` When both `request.user.userprofile.gym` and `user.userprofile.gym` are `None`, Python evaluates `None != None` as `False`, and `HttpResponseForbidden` is never reached. The subsequent queryset applies only the attacker-supplied `member` (user ID) as a filter — there is no secondary check tying the queryset to the requesting trainer's gym. All ",
    "evidence": "osv:PYSEC-2026-4313",
    "products": [
      {
        "name": {
          "value": "wger",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.1.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.2rc1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.3",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.4",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.5",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.6",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.6.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.7",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.8",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.9",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.0",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2.1",
            "evidence": "/affected/0/versions"
          }
        ]
      }
    ],
    "severity": "high",
    "structured": {
      "id": "PYSEC-2026-4313",
      "aliases": [
        "CVE-2026-43976",
        "GHSA-c72h-82w6-rqfp",
        "PYSEC-2026-4313"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "2.1"
                }
              ]
            }
          ],
          "package": {
            "name": "wger",
            "purl": "pkg:pypi/wger",
            "ecosystem": "PyPI"
          },
          "versions": [
            "1.1",
            "1.1.1",
            "1.2",
            "1.2rc1",
            "1.3",
            "1.4",
            "1.5",
            "1.6",
            "1.6.1",
            "1.7",
            "1.8",
            "1.9",
            "2.0",
            "2.1"
          ],
          "database_specific": {
            "source": "https://github.com/pypa/advisory-database/blob/main/vulns/wger/PYSEC-2026-4313.yaml"
          }
        }
      ],
      "modified": "2026-10-15T14:45:10.349862114Z",
      "provider": "osv",
      "references": [
        "https://github.com/wger-project/wger/security/advisories/GHSA-c72h-82w6-rqfp",
        "https://github.com/wger-project/wger",
        "https://github.com/wger-project/wger/releases/tag/2.6",
        "https://pypi.org/project/wger",
        "https://github.com/advisories/GHSA-c72h-82w6-rqfp",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-43976"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-43976",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 332651,
  "published_at": "2026-10-15T10:22:46.832742+00:00"
}