Craft CMS: Potential authenticated Remote Code Execution via malicious attached Behavior

{
  "id": "310d26a075a10e689fccafd0d332b25230c7d98843b8eaa12a493c06531e6e52",
  "url": "https://osv.dev/vulnerability/CVE-2026-33157",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Craft CMS: Potential authenticated Remote Code Execution via malicious attached Behavior",
    "summary": "Craft CMS is a content management system (CMS). From version 5.6.0 to before version 5.9.13, a Remote Code Execution (RCE) vulnerability exists in Craft CMS, it can be exploited by any authenticated user with control panel access. This is a bypass of a previous fix. The existing patches add cleanseConfig() to assembleLayoutFromPost() and various FieldsController actions to strip Yii2 behavior/event injection keys (\"as\" and \"on\" prefixed keys). However, the fieldLayouts parameter in ElementIndexesController::actionFilterHud() is passed directly to FieldLayout::createFromConfig() without any sanitization, enabling the same behavior injection attack chain. This issue has been patched in version 5.9.13.",
    "evidence": "osv:CVE-2026-33157",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-33157",
      "aliases": [
        "CVE-2026-33157",
        "GHSA-2fph-6v5w-89hh"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/craftcms/cms",
              "type": "GIT",
              "events": [
                {
                  "introduced": "e14cba6cdca8902c3efb0549a5dc290002b750c2"
                },
                {
                  "fixed": "79198636a24ce405d8365e1bc281b3405313ccbf"
                },
                {
                  "fixed": "97e90b4bdee369c1af3ca77a77531132df240e4e"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:craftcms:craft_cms:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "5.6.0"
                      },
                      {
                        "fixed": "5.9.13"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "97e90b4bdee369c1af3ca77a77531132df240e4e"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "79198636a24ce405d8365e1bc281b3405313ccbf"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "5.9.13"
                  }
                ]
              }
            }
          ],
          "versions": [
            "5.9.3",
            "5.9.12",
            "5.9.11",
            "5.9.10",
            "5.9.9",
            "5.9.8",
            "5.9.7",
            "5.9.6",
            "5.9.5",
            "5.9.4",
            "5.9.2",
            "5.9.1",
            "5.9.0",
            "5.9.0-beta.2",
            "5.9.0-beta.1",
            "5.8.23",
            "5.8.22",
            "5.8.21",
            "5.8.20",
            "5.8.19",
            "5.8.18",
            "5.8.17",
            "5.8.16",
            "5.8.15",
            "5.8.14",
            "5.8.13.2",
            "5.8.13.1",
            "5.8.13",
            "5.8.12",
            "5.8.11",
            "5.8.10",
            "5.8.9",
            "5.8.8",
            "5.8.7",
            "5.8.6",
            "5.8.5",
            "5.8.4",
            "5.8.3",
            "5.8.2",
            "5.8.1",
            "5.8.0",
            "5.7.11",
            "5.7.10",
            "5.7.9",
            "5.7.8.2",
            "5.7.8.1",
            "5.7.8",
            "5.7.7",
            "5.7.6",
            "5.7.5",
            "5.7.4",
            "5.7.3",
            "5.7.2",
            "5.7.1.1",
            "5.7.1",
            "5.7.0",
            "5.6.17",
            "5.6.16",
            "5.6.15",
            "5.6.14",
            "5.6.13",
            "5.6.12",
            "5.6.11",
            "5.6.10.2",
            "5.6.10.1",
            "5.6.10",
            "5.6.9.1",
            "5.6.9",
            "5.6.8",
            "5.6.7",
            "5.6.6",
            "5.6.5.1",
            "5.6.5",
            "5.6.4",
            "5.6.3",
            "5.6.2",
            "5.6.1",
            "5.6.0.2",
            "5.6.0.1",
            "5.6.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33157.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.789239335Z",
      "provider": "osv",
      "references": [
        "https://github.com/craftcms/cms/releases/tag/5.9.13",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33157.json",
        "https://github.com/craftcms/cms/security/advisories/GHSA-2fph-6v5w-89hh",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-33157",
        "https://github.com/craftcms/cms/commit/97e90b4bdee369c1af3ca77a77531132df240e4e"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-470"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33157.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-33157",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 518464,
  "published_at": "2026-03-24T17:22:00.966+00:00"
}