In Concrete CMS 9.2.0 to 9.5.2, Missing Authorization in REST API Users update() and change_password Enables Account Takeover.

{
  "id": "77d84ffb2abd397de153d24ce04b95f8583ee1056e8e2d18b5e77031dc48b479",
  "url": "https://osv.dev/vulnerability/CVE-2026-18115",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "In Concrete CMS 9.2.0 to 9.5.2, Missing Authorization in REST API Users update() and change_password Enables Account Takeover.",
    "summary": "Concrete CMS 9.2.0 to 9.5.2 did not enforce per-field edit_user_properties permissions on the REST API user write endpoints (PUT /ccm/api/1.0/users/{uID} and POST /ccm/api/1.0/users/{uID}/change_password). A user with an update-scoped OAuth token and permission to edit only one non-sensitive field could change another non-superuser's password, username, email, and attributes, taking over that account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.4 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.",
    "evidence": "osv:CVE-2026-18115",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-18115",
      "aliases": [
        "CVE-2026-18115"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/concretecms/concretecms",
              "type": "GIT",
              "events": [
                {
                  "introduced": "6462c74b64a9d8919cc4a16f78880079dc6878ff"
                },
                {
                  "last_affected": "8fe9708072c3815a5df719b592e4b23b43b4ff7a"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "9.2.0"
                      },
                      {
                        "last_affected": "9.5.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-18115.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:30.408627339Z",
      "provider": "osv",
      "references": [
        "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18115.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-18115",
        "https://github.com/concretecms/concretecms"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-862"
        ],
        "cna_assigner": "ConcreteCMS",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18115.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-18115",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 497130,
  "published_at": "2026-09-15T17:39:04.359+00:00"
}