Open WebUI: Calendar event re-parenting allows writing events into another user's calendar

{
  "id": "630f384c85515d0b0183b31f5250a96b5e62905353fd698e30cb3a5ff50d5ff2",
  "url": "https://osv.dev/vulnerability/CVE-2026-54006",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Open WebUI: Calendar event re-parenting allows writing events into another user's calendar",
    "summary": "Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, POST /api/v1/calendars/events/{event_id}/update validates that the caller has write access to the calendar the event currently belongs to, but does not validate the destination calendar_id supplied in the request body. The model layer then persists the new calendar_id unconditionally. A regular user-role account can therefore create an event in their own calendar and immediately move it into any other user's calendar whose ID they know — bypassing the authorization check that create_event correctly performs. This vulnerability is fixed in 0.9.6.",
    "evidence": "osv:CVE-2026-54006",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-54006",
      "aliases": [
        "CVE-2026-54006",
        "GHSA-f3g7-59qc-pqg6",
        "PYSEC-2026-2722"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/open-webui/open-webui",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1a97751e376e00a1897bc3679215ae1c7bd8fd42"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.9.6"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.9.6"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54006.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:50.383770186Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54006.json",
        "https://github.com/open-webui/open-webui/security/advisories/GHSA-f3g7-59qc-pqg6",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-54006"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-639"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54006.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-54006",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 518905,
  "published_at": "2026-06-23T16:50:44.406+00:00"
}