Craft CMS 5.0.0 before 5.10.13 Broken Access Control via nested-elements/reorder

{
  "id": "3ce0068c50443a33484096fe49df60a7003790c9e7a03197e6129e6f6b6d16d8",
  "url": "https://osv.dev/vulnerability/CVE-2026-92589",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Craft CMS 5.0.0 before 5.10.13 Broken Access Control via nested-elements/reorder",
    "summary": "Craft CMS 5.0.0 through 5.10.12 (fixed in 5.10.13) contains a broken access control flaw in the nested-elements reorder endpoint. When an authenticated control panel user with viewEntries and viewPeerEntries (but without savePeerEntries) opens another author's entry in read-only mode, Craft unconditionally grants that session a `manageNestedElements::::field:` authorization flag for the entry's Matrix/Address fields. Unlike the corresponding delete endpoint, actions/nested-elements/reorder trusts this session flag alone and never rechecks the caller's save permission for the owner element. As a result, a view-only user can POST to actions/nested-elements/reorder using the ownerElementType, ownerId, ownerSiteId, attribute, elementIds, and offset parameters present in the read-only page source and rewrite the sort order of Matrix blocks or Addresses belonging to content they are explicitly denied save access to.",
    "evidence": "osv:CVE-2026-92589",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-92589",
      "aliases": [
        "CVE-2026-92589",
        "GHSA-6fp2-8j9w-7mj8"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/craftcms/cms",
              "type": "GIT",
              "events": [
                {
                  "introduced": "f6a8fb685d44e387435825e3a96809eeda4973a6"
                },
                {
                  "fixed": "0b18123e8c3be1edcf6f785e9925e1b1007ce8c5"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "5.0.0"
                      },
                      {
                        "fixed": "5.10.13"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-92589.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.631507810Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/92xxx/CVE-2026-92589.json",
        "https://github.com/craftcms/cms/security/advisories/GHSA-6fp2-8j9w-7mj8",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-92589",
        "https://www.vulncheck.com/advisories/craft-cms-5.0.0-before-5.10.13-broken-access-control-via-nested-elements-reorder"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-862"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/92xxx/CVE-2026-92589.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-92589",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517906,
  "published_at": "2026-09-16T21:46:55.216+00:00"
}