{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.4.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "36cdc2ce2be0b8ccc74227d178b92047d59cd65f"
            },
            {
              "fixed": "907850feae3866ae9b16ea1c7b84a4d77273415a"
            }
          ],
          "repo": "https://github.com/go-vikunja/vikunja",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-5pg6-m483-7vrg"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-639"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55066.json"
  },
  "details": "Vikunja is an open-source self-hosted task management platform. Prior to 2.4.0, POST /api/v1/projects/{project}/views/{view}/buckets/{bucket}/tasks accepts a body supplied task_id but TaskBucket.CanUpdate in pkg/models/kanban_task_bucket.go authorizes only the project, view, and bucket from the URL. updateTaskBucket then calls Task.ReadOne without a separate task permission check, returns the victim task contents, and can update the task done state when the attacker chooses a done bucket. Because task identifiers are global sequential values, an authenticated user can enumerate cross-tenant tasks and modify their completion metadata through both the v1 and v2 routes that share this model. This issue is fixed in version 2.4.0.",
  "id": "CVE-2026-55066",
  "modified": "2026-09-11T03:30:26.305466469Z",
  "published": "2026-08-28T16:51:48.114Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55066.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-5pg6-m483-7vrg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55066"
    },
    {
      "type": "FIX",
      "url": "https://github.com/go-vikunja/vikunja/commit/36cdc2ce2be0b8ccc74227d178b92047d59cd65f"
    },
    {
      "type": "FIX",
      "url": "https://github.com/go-vikunja/vikunja/pull/3239"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Vikunja: Cross-tenant IDOR in kanban move-task endpoint via unauthorized body task_id"
}