{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "vikunja",
          "vendor": "go-vikunja",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.4.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-639",
              "description": "CWE-639: Authorization Bypass Through User-Controlled Key",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-28T16:51:48.114Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-5pg6-m483-7vrg",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-5pg6-m483-7vrg"
        },
        {
          "name": "https://github.com/go-vikunja/vikunja/pull/3239",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/go-vikunja/vikunja/pull/3239"
        },
        {
          "name": "https://github.com/go-vikunja/vikunja/commit/36cdc2ce2be0b8ccc74227d178b92047d59cd65f",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/go-vikunja/vikunja/commit/36cdc2ce2be0b8ccc74227d178b92047d59cd65f"
        },
        {
          "name": "https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0"
        }
      ],
      "source": {
        "advisory": "GHSA-5pg6-m483-7vrg",
        "discovery": "UNKNOWN"
      },
      "title": "Vikunja: Cross-tenant IDOR in kanban move-task endpoint via unauthorized body task_id"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-55066",
    "datePublished": "2026-08-28T16:51:48.114Z",
    "dateReserved": "2026-06-16T14:33:35.710Z",
    "dateUpdated": "2026-08-28T16:51:48.114Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}