Vikunja: Link-share token reads any tenant's kanban buckets and enumerates usernames/IDs instance-wide (BOLA)

{
  "id": "d70441a3145be9998fb3c4965086074e58408e1ac1985c34e4174d84645a4312",
  "url": "https://osv.dev/vulnerability/GHSA-rj9j-8772-4h6c",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Vikunja: Link-share token reads any tenant's kanban buckets and enumerates usernames/IDs instance-wide (BOLA)",
    "summary": "## Summary The task-collection endpoint `GET /api/v1/projects/{project}/views/{view}/tasks` loads the requested project view straight from the URL path without verifying the caller is authorized for it. For a **link-share token**, the task query is correctly pinned to the share's own project, but the *view* is taken from the attacker-controlled path and never re-validated against the share. A holder of a share link to **any** project can therefore point the endpoint at any other tenant's kanban view and receive that view's bucket records — bucket titles plus the full `created_by` user object (username, name, id) — for every view in the instance. The same missing pre-authorization view load also yields a project/view-ID existence oracle (404 vs. non-404) usable by link shares and ordinary authenticated users alike. ## Details Root cause is in `TaskCollection.ReadAll` (`pkg/models/task_collection.go`). 1. The view is resolved from the URL params before any permission check: ```go // pkg/models/task_collection.go (ReadAll) if tf.ProjectViewID != 0 { view, err = GetProjectViewByIDAndProject(s, tf.ProjectViewID, tf.ProjectID) // (URL params) ... } ``` `GetProjectViewByIDAndProject` (`pkg/models/project_view.go`) filters only on `WHERE id = ? AND project_id = ?` — it performs no authorization. A valid `(project, view)` pair returns the view; an invalid pair returns `ErrProjectViewDoesNotExist` (HTTP 404). 2. For a link-share caller, the code pins the *task* scope to the token's own",
    "evidence": "osv:GHSA-rj9j-8772-4h6c",
    "products": [
      {
        "name": {
          "value": "code.vikunja.io/api",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.4.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "GHSA-rj9j-8772-4h6c",
      "aliases": [
        "CVE-2026-68582",
        "GHSA-rj9j-8772-4h6c",
        "GO-2026-6749"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0.24.0"
                },
                {
                  "fixed": "2.4.0"
                }
              ]
            }
          ],
          "package": {
            "name": "code.vikunja.io/api",
            "purl": "pkg:golang/code.vikunja.io/api",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-rj9j-8772-4h6c/GHSA-rj9j-8772-4h6c.json",
            "last_known_affected_version_range": "<= 2.3.0"
          }
        }
      ],
      "modified": "2026-10-19T21:41:11.703411636Z",
      "provider": "osv",
      "references": [
        "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-rj9j-8772-4h6c",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-68582",
        "https://github.com/go-vikunja/vikunja",
        "https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0",
        "https://www.vulncheck.com/advisories/vikunja-broken-object-level-authorization-via-link-share-token"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-639",
          "CWE-863"
        ],
        "severity": "CRITICAL",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-09T20:42:33Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-68582",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 376782,
  "published_at": "2026-10-09T20:42:33+00:00"
}