{"id":"GHSA-533c-2vh9-4r86","summary":"Decidim: HTML content blocks allow stored script execution","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's 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's 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/).","aliases":["CVE-2026-45572"],"modified":"2026-07-13T17:41:46.531106Z","published":"2026-07-13T17:18:12Z","database_specific":{"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-07-13T17:18:12Z","nvd_published_at":null,"cwe_ids":["CWE-94"]},"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"}],"affected":[{"package":{"name":"decidim-core","ecosystem":"RubyGems","purl":"pkg:gem/decidim-core"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.30.9"}]}],"versions":["0.0.1","0.0.1.alpha1","0.0.1.alpha2","0.0.1.alpha3","0.0.1.alpha4","0.0.1.alpha5","0.0.1.alpha6","0.0.1.alpha7","0.0.1.alpha8","0.0.1.alpha9","0.0.2","0.0.3","0.0.5","0.0.6","0.0.7","0.0.8.1","0.1.0","0.10.0","0.10.1","0.11.0.pre1","0.11.1","0.11.2","0.12.0","0.12.0.pre","0.12.1","0.12.2","0.13.0","0.13.0.pre1","0.13.1","0.14.1","0.14.2","0.14.3","0.14.4","0.15.0","0.15.1","0.15.2","0.16.0","0.16.1","0.17.0","0.17.1","0.17.2","0.18.0","0.18.1","0.19.0","0.19.1","0.2.0","0.20.0","0.20.1","0.21.0","0.22.0","0.23.0","0.23.1","0.23.1.rc1","0.23.2","0.23.3","0.23.4","0.23.5","0.23.6","0.24.0","0.24.0.rc1","0.24.0.rc2","0.24.1","0.24.2","0.24.3","0.25.0","0.25.0.rc1","0.25.0.rc2","0.25.0.rc3","0.25.0.rc4","0.25.1","0.25.2","0.26.0","0.26.0.rc1","0.26.0.rc2","0.26.1","0.26.10","0.26.2","0.26.3","0.26.4","0.26.5","0.26.7","0.26.8","0.26.9","0.27.0","0.27.0.rc1","0.27.0.rc2","0.27.1","0.27.10","0.27.2","0.27.3","0.27.4","0.27.5","0.27.6","0.27.7","0.27.8","0.27.9","0.28.0","0.28.0.rc4","0.28.0.rc5","0.28.1","0.28.2","0.28.3","0.28.4","0.28.5","0.28.6","0.29.0","0.29.0.rc1","0.29.0.rc2","0.29.0.rc3","0.29.0.rc4","0.29.1","0.29.2","0.29.3","0.29.4","0.29.5","0.29.6","0.29.7","0.3.0","0.3.1","0.3.2","0.30.0","0.30.0.rc1","0.30.0.rc2","0.30.0.rc3","0.30.1","0.30.2","0.30.3","0.30.4","0.30.5","0.30.6","0.30.7","0.30.8","0.4.0","0.4.1","0.4.2","0.4.3","0.4.4","0.5.0","0.5.1","0.6.0","0.6.1","0.6.2","0.6.3","0.6.4","0.6.5","0.6.6","0.6.7","0.6.8","0.7.0","0.7.1","0.7.2","0.7.3","0.7.4","0.8.0","0.8.1","0.8.2","0.8.3","0.8.4","0.9.0","0.9.1","0.9.2","0.9.3"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-533c-2vh9-4r86/GHSA-533c-2vh9-4r86.json"}},{"package":{"name":"decidim-core","ecosystem":"RubyGems","purl":"pkg:gem/decidim-core"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.31.0.rc1"},{"fixed":"0.31.5"}]}],"versions":["0.31.0","0.31.0.rc1","0.31.0.rc2","0.31.1","0.31.2","0.31.3","0.31.4"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-533c-2vh9-4r86/GHSA-533c-2vh9-4r86.json"}},{"package":{"name":"decidim-core","ecosystem":"RubyGems","purl":"pkg:gem/decidim-core"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.32.0.rc1"},{"fixed":"0.32.0"}]}],"versions":["0.32.0.rc1","0.32.0.rc2","0.32.0.rc3"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-533c-2vh9-4r86/GHSA-533c-2vh9-4r86.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N"}]}