{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "loofah"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.25.0"
            },
            {
              "fixed": "2.25.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.25.0"
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-18T17:26:48Z",
    "nvd_published_at": null,
    "severity": "LOW"
  },
  "details": "## Summary\n\n`Loofah::HTML5::Scrub.allowed_uri?` does not correctly reject `javascript:` URIs when the scheme is split by HTML entity-encoded control characters such as `\u0026#13;` (carriage return), `\u0026#10;` (line feed), or `\u0026#9;` (tab).\n\n## Details\n\nThe `allowed_uri?` method strips literal control characters before decoding HTML entities. Payloads like `java\u0026#13;script:alert(1)` survive the control character strip, then `\u0026#13;` is decoded to a carriage return, producing `java\\rscript:alert(1)`.\n\nNote that the Loofah sanitizer\u0027s default `sanitize()` path is **not affected** because Nokogiri decodes HTML entities during parsing before Loofah evaluates the URI protocol. This issue only affects direct callers of the `allowed_uri?` string-level helper when passing HTML-encoded strings.\n\n## Impact\n\nApplications that call `Loofah::HTML5::Scrub.allowed_uri?` to validate user-controlled URLs and then render approved URLs into `href` or other browser-interpreted URI attributes may be vulnerable to cross-site scripting (XSS).\n\nThis only affects Loofah `2.25.0`.\n\n## Mitigation\n\nUpgrade to Loofah \u003e= `2.25.1`.\n\n## Credit\n\nResponsibly reported by HackOne user `@smlee`.",
  "id": "GHSA-46fp-8f5p-pf2m",
  "modified": "2026-03-18T17:26:48Z",
  "published": "2026-03-18T17:26:48Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/flavorjones/loofah/security/advisories/GHSA-46fp-8f5p-pf2m"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/flavorjones/loofah"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Improper detection of disallowed URIs by Loofah `allowed_uri?`"
}