{"id":"GHSA-2vcc-5v34-9jc8","summary":"TinaCMS rich-text (slatejson) rendering does not sanitize link/image URLs, allowing stored XSS via dangerous URL schemes","details":"TinaCMS rich-text parsing and the default link/image renderers did not sanitize the `url` field on Slate link/image nodes. Content containing `javascript:` or `data:text/html` URLs — including case-variant, whitespace-padded, and control-character-obfuscated forms — is rendered into `href`/`src` and executes when the content is viewed. Any actor able to author rich-text content (for example a lower-privileged editor, or imported/external content) can achieve stored XSS against editors and site viewers.\n\nFixed in https://github.com/tinacms/tinacms/pull/7056 via a `sanitizeUrl()` helper (case-insensitive, whitespace/control-character-normalized scheme allow-list) applied recursively to Slate trees at parse time and in the default rich-text rendering.","aliases":["CVE-2026-55661"],"modified":"2026-09-10T03:50:55.365499184Z","published":"2026-06-18T13:07:05Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-06-18T13:07:05Z","nvd_published_at":null,"cwe_ids":["CWE-79","CWE-87"],"severity":"MODERATE"},"references":[{"type":"WEB","url":"https://github.com/tinacms/tinacms/security/advisories/GHSA-2vcc-5v34-9jc8"},{"type":"WEB","url":"https://github.com/tinacms/tinacms/pull/7056"},{"type":"PACKAGE","url":"https://github.com/tinacms/tinacms"}],"affected":[{"package":{"name":"tinacms","ecosystem":"npm","purl":"pkg:npm/tinacms"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.9.3"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-2vcc-5v34-9jc8/GHSA-2vcc-5v34-9jc8.json"}},{"package":{"name":"@tinacms/mdx","ecosystem":"npm","purl":"pkg:npm/%40tinacms/mdx"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.1.7"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-2vcc-5v34-9jc8/GHSA-2vcc-5v34-9jc8.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"}]}