ghsa-9wjq-cp2p-hrgf

CVSS 4.7 osv_rubygems
Description

## Summary Loofah's HTML5 sanitizer restricted only the `xlink:href` attribute on certain SVG elements to local, same-document references. Browsers also accept a plain `href` attribute as an alternative to the deprecated `xlink:href` per the SVG 2 spec, but Loofah did not apply the same restriction to it, allowing those elements to reference arbitrary external documents. ## Impact SVG `<use>` can load and render external SVG content by reference. If the referenced external SVG is same-origin and contains scripts or other dangerous content, it could execute in the context of the sanitized document. `<feImage>` can load external images, which can be used for tracking. Modern browsers restrict cross-origin `<use>` fetches, which limits but does not eliminate the risk. Applications that sanitize user-supplied SVG (directly, or as part of HTML) with Loofah's default allowlist are affected. ## Mitigation Upgrade to Loofah >= 2.25.2. ## Credit Found by the maintainer, Mike Dalessio, during a security audit.

Timeline
Published
unknown
Last Modified
unknown
CVSS Details

CVSS details not available.

Affected Products

No product information available.

Weaknesses (CWE)
References
Linked Vulnerabilities

No linked vulnerabilities found.

{
  "affected": [
    {
      "database_specific": {
        "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-9wjq-cp2p-hrgf/GHSA-9wjq-cp2p-hrgf.json"
      },
      "package": {
        "ecosystem": "RubyGems",
        "name": "loofah",
        "purl": "pkg:gem/loofah"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.25.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.2.0",
        "0.2.1",
        "0.2.2",
        "0.3.0",
        "0.3.1",
        "0.4.0",
        "0.4.1",
        "0.4.2",
        "0.4.3",
        "0.4.4",
        "0.4.5",
        "0.4.6",
        "0.4.7",
        "1.0.0",
        "1.0.0.beta.1",
        "1.1.0",
        "1.2.0",
        "1.2.1",
        "2.0.0",
        "2.0.1",
        "2.0.2",
        "2.0.3",
        "2.1.0",
        "2.1.0.rc1",
        "2.1.0.rc2",
        "2.1.1",
        "2.10.0",
        "2.11.0",
        "2.12.0",
        "2.13.0",
        "2.14.0",
        "2.15.0",
        "2.16.0",
        "2.17.0",
        "2.18.0",
        "2.19.0",
        "2.19.1",
        "2.2.0",
        "2.2.1",
        "2.2.2",
        "2.2.3",
        "2.20.0",
        "2.21.0",
        "2.21.0.rc1",
        "2.21.1",
        "2.21.2",
        "2.21.3",
        "2.21.4",
        "2.22.0",
        "2.23.0",
        "2.23.1",
        "2.24.0",
        "2.24.1",
        "2.25.0",
        "2.25.1",
        "2.3.0",
        "2.3.1",
        "2.4.0",
        "2.5.0",
        "2.6.0",
        "2.7.0",
        "2.8.0",
        "2.9.0",
        "2.9.1"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-73490"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-21T22:01:58Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nLoofah's HTML5 sanitizer restricted only the `xlink:href` attribute on certain SVG elements to local, same-document references. Browsers also accept a plain `href` attribute as an alternative to the deprecated `xlink:href` per the SVG 2 spec, but Loofah did not apply the same restriction to it, allowing those elements to reference arbitrary external documents.\n\n## Impact\n\nSVG `<use>` can load and render external SVG content by reference. If the referenced external SVG is same-origin and contains scripts or other dangerous content, it could execute in the context of the sanitized document. `<feImage>` can load external images, which can be used for tracking. Modern browsers restrict cross-origin `<use>` fetches, which limits but does not eliminate the risk.\n\nApplications that sanitize user-supplied SVG (directly, or as part of HTML) with Loofah's default allowlist are affected.\n\n## Mitigation\n\nUpgrade to Loofah >= 2.25.2.\n\n## Credit\n\nFound by the maintainer, Mike Dalessio, during a security audit.",
  "id": "GHSA-9wjq-cp2p-hrgf",
  "modified": "2026-09-10T03:51:11.411106078Z",
  "published": "2026-07-21T22:01:58Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/flavorjones/loofah/security/advisories/GHSA-9wjq-cp2p-hrgf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/flavorjones/loofah/commit/20867b9be689521887364b74822c41ef830523c9"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/flavorjones/loofah"
    },
    {
      "type": "WEB",
      "url": "https://github.com/flavorjones/loofah/releases/tag/v2.25.2"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Loofah: SVG `href` attribute bypasses local-reference restriction"
}
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