Flextype CMS 0.9.9 through 1.0.0-alpha.3 Stored XSS via Plugin Directory

{
  "id": "d3eb2ef7974ab8735dec2171cd87308dc25ca2dab276d1a7d6b3be0496af92e4",
  "url": "https://osv.dev/vulnerability/CVE-2026-89145",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Flextype CMS 0.9.9 through 1.0.0-alpha.3 Stored XSS via Plugin Directory",
    "summary": "Flextype CMS versions 0.9.9 through 1.0.0-alpha.3 fail to HTML-escape plugin directory names in the dependency error page rendered by getValidPluginsDependencies(). Attackers with write access to the plugins directory can create a plugin with HTML characters in its name to execute arbitrary scripts in users' browsers when dependency validation fails.",
    "evidence": "osv:CVE-2026-89145",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-89145",
      "aliases": [
        "CVE-2026-89145"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/flextype/flextype",
              "type": "GIT",
              "events": [
                {
                  "introduced": "a30429fbf157033804430a287cb3c71ec744daef"
                },
                {
                  "last_affected": "aea4ead8c449ea5517ed53b6dcbd28b0a528ad9d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0.9.9"
                      },
                      {
                        "last_affected": "1.0.0-alpha.3"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0.9.9"
                      },
                      {
                        "last_affected": "1.0.0-alpha.3"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.0.0-alpha.3",
            "v1.0.0-alpha.2",
            "v1.0.0-alpha.1",
            "v0.9.16",
            "v0.9.15",
            "v0.9.14",
            "v0.9.13",
            "v0.9.12",
            "v0.9.11",
            "v0.9.10",
            "v0.9.9"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89145.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:52.511083707Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89145.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-89145",
        "https://www.vulncheck.com/advisories/flextype-cms-0.9.9-through-1.0.0-alpha.3-stored-xss-via-plugin-directory",
        "https://github.com/flextype/flextype/issues/597",
        "https://github.com/flextype/flextype",
        "https://github.com/flextype/flextype/blob/aea4ead8c449ea5517ed53b6dcbd28b0a528ad9d/src/flextype/core/Plugins.php#L345"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89145.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-89145",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 521299,
  "published_at": "2026-09-11T01:14:20.554+00:00"
}