Nextcloud: Missing permission check for from submissions

{
  "id": "1de0f021cdac697d871d881a1c8c2c62e8c0103c7a6be10f2eecc42f21422b02",
  "url": "https://osv.dev/vulnerability/CVE-2026-45267",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Nextcloud: Missing permission check for from submissions",
    "summary": "Nextcloud is an open source content collaboration platform. Prior to version 5.2.6, a missing permissions check allowed users to request reading form submissions of other users. This issue has been patched in version 5.2.6.",
    "evidence": "osv:CVE-2026-45267",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-45267",
      "aliases": [
        "CVE-2026-45267",
        "GHSA-r4gh-f8x6-m55f"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/nextcloud/forms",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3e6b73535bb670e0b46c47c4333c8071f6009657"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "5.2.6"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "5.2.6"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v5.2.5",
            "v5.2.4",
            "v5.2.3",
            "v5.2.2",
            "v5.2.1",
            "v5.2.0",
            "v5.2.0-beta.2",
            "v5.2.0-beta.1",
            "v5.2.0-beta.0",
            "v5.1.0",
            "v5.0.4",
            "v5.0.3",
            "v5.0.2",
            "v5.0.1",
            "v5.0.0",
            "v5.0.0-alpha.3",
            "v5.0.0-alpha.2",
            "v5.0.0-alpha.1",
            "v5.0.0-alpha.0",
            "v4.3.0",
            "v4.3.0-alpha7",
            "v4.3.0-alpha6",
            "v4.3.0-alpha5",
            "v4.3.0-alpha4",
            "v4.3.0-alpha3",
            "v4.2.3",
            "v4.2.2",
            "v4.2.1",
            "v4.2.0",
            "v4.2.0-alpha.1",
            "v4.1.1",
            "v4.1.0",
            "v4.0.0",
            "v4.0.0-alpha.2",
            "v4.0.0-alpha.1",
            "v3.4.0",
            "v3.3.1",
            "v3.3.0",
            "v3.2.0",
            "v3.1.0",
            "v3.0.4",
            "v3.0.3",
            "v3.0.2",
            "v3.0.1",
            "v3.0.0",
            "v3.0.0-beta.2",
            "v3.0.0-beta.1",
            "v2.5.0",
            "v2.4.0",
            "v2.3.0",
            "v2.3.0-alpha.0",
            "v2.2.4",
            "v2.2.3",
            "v2.2.2",
            "v2.2.1",
            "v2.2.0",
            "v2.2.0-beta.1",
            "v2.1.0",
            "v2.0.4",
            "v2.0.3",
            "v2.0.2",
            "v2.0.0",
            "v2.0.0-rc.1",
            "v2.0.0-beta.4",
            "v2.0.0-beta.3",
            "v2.0.0-beta2",
            "v2.0.0-beta1",
            "v1.1.1",
            "v1.1.0",
            "v.1.0.4",
            "v1.0.3"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45267.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:36.038770111Z",
      "provider": "osv",
      "references": [
        "https://hackerone.com/reports/3628817",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45267.json",
        "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-r4gh-f8x6-m55f",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-45267",
        "https://github.com/nextcloud/forms/pull/3269"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-200",
          "CWE-862"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45267.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-45267",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 503366,
  "published_at": "2026-06-01T16:40:18.592+00:00"
}