{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "2.25.0"
                  },
                  {
                    "fixed": "2.25.3"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              },
              {
                "range": [
                  {
                    "fixed": "62c04841e8252a1b5373afcd2b89fb9b8279e317"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "original_tag": "v2.25.3",
                "range": [
                  {
                    "fixed": "bbe007e52e8aeaa520b3e515235d467f5b1416e6"
                  }
                ],
                "source": "REFERENCES_TAG"
              }
            ]
          },
          "events": [
            {
              "introduced": "e65bdddfd3381f3a131be7e137d89bb3959c072b"
            },
            {
              "fixed": "bbe007e52e8aeaa520b3e515235d467f5b1416e6"
            },
            {
              "fixed": "62c04841e8252a1b5373afcd2b89fb9b8279e317"
            }
          ],
          "repo": "https://github.com/flavorjones/loofah",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-p9wj-w8xq-vjx6"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-184",
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126209.json"
  },
  "details": "Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. From 2.25.0 until 2.25.3, Loofah::HTML5::Scrub.allowed_uri? strips whitespace and control characters before decoding a semicolon-less numeric character reference, changing where the reference ends and hiding a javascript: or vbscript: scheme that a browser reconstructs. The bypass applies to encoded colons and encoded scheme letters when a stripped character terminates the numeric reference. An application that renders the approved value in href or another browser-interpreted URI attribute can allow cross-site scripting, and Rails::HTML::Sanitizer.allowed_uri? re-exports the affected helper. Loofah's default sanitize() path is not affected because Nokogiri decodes entities before URI evaluation. This issue is fixed in version 2.25.3.",
  "id": "CVE-2026-126209",
  "modified": "2026-11-14T02:30:50.136850910Z",
  "published": "2026-11-12T21:01:58.128Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/flavorjones/loofah/releases/tag/v2.25.3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126209.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/flavorjones/loofah/security/advisories/GHSA-p9wj-w8xq-vjx6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-126209"
    },
    {
      "type": "FIX",
      "url": "https://github.com/flavorjones/loofah/commit/62c04841e8252a1b5373afcd2b89fb9b8279e317"
    },
    {
      "type": "FIX",
      "url": "https://github.com/flavorjones/loofah/pull/324"
    }
  ],
  "schema_version": "1.9.2",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Loofah allowed_uri? treats javascript\u0026#x3a alert(1) as safe"
}