{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "decidim-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.30.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "decidim-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.31.0.rc1"
            },
            {
              "fixed": "0.31.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "decidim-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.32.0.rc1"
            },
            {
              "fixed": "0.32.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45572"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-13T17:18:12Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Description\n \nA privileged admin user who can edit an affected landing page can store arbitrary HTML/JavaScript in an `HTML block`, and the public page renders it with `html_safe` and no output escaping.\n\n## Technical description\n    \nThis issue lets any admin who can edit an affected landing page store arbitrary HTML and JavaScript in an `HTML block`. The block is then rendered back through `Decidim::ContentBlocks::HtmlCell#html_content` without a sanitization boundary, so the script executes later in visitor\u0027s browsers.\n\n\u003cimg width=\"1541\" height=\"439\" alt=\"decidim-html-xss-01\" src=\"https://github.com/user-attachments/assets/acae1c06-8acb-49be-ab12-aabae33190ce\" /\u003e\n\n\u003cimg width=\"1540\" height=\"752\" alt=\"decidim-html-xss-02\" src=\"https://github.com/user-attachments/assets/a2f1fa7f-03f3-4d17-b58b-f4db865443e9\" /\u003e\n\n\n### Impact\n\n- A user with landing-page editing rights for an affected scope can persist JavaScript that executes in visitor\u0027s browsers on that page.\n- Because exploitation already requires privileged administrative access, the practical risk is lower than a participant-controlled or unauthenticated stored XSS. It still creates a browser-execution primitive in a trusted admin-editable surface.\n\n### Patches\n\nSee https://github.com/decidim/decidim/pull/16451 \n\n### Workarounds\n\nDo not give admin permissions to non-trustful users. \n\n### Reference\n\nStored XSS\n\n### Credits\n\nThis issue was discovered in a security audit organized by the [Decidim Association](https://decidim.org) and made by [Radically Open Security](https://www.radicallyopensecurity.com/) against Decidim financed by [NGI](https://ngi.eu/).",
  "id": "GHSA-533c-2vh9-4r86",
  "modified": "2026-07-13T17:18:12Z",
  "published": "2026-07-13T17:18:12Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/decidim/decidim/security/advisories/GHSA-533c-2vh9-4r86"
    },
    {
      "type": "WEB",
      "url": "https://github.com/decidim/decidim/pull/16451"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/decidim/decidim"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Decidim: HTML content blocks allow stored script execution"
}