{"schema_version":"1.9.0","id":"GHSA-27mw-82g8-phjj","published":"2026-10-23T20:43:30Z","modified":"2026-10-23T21:00:04.312966515Z","aliases":["CVE-2026-114061"],"summary":"SvelteKit : XSS via untrusted cache-control header in prerendered page","details":"### Impact\n\nApplications that prerender pages and use `setHeaders` to set a `cache-control` header from an untrusted source are vulnerable to cross-site scripting (XSS).\n\nSvelteKit inserts the header value into a `<meta http-equiv=\"cache-control\">` tag without escaping it. An attacker who can influence this value at prerender time can break out of the `content` attribute and inject HTML or JavaScript into the generated page. The injected code can then execute when users visit the page.\n\n### Patches\n\nThe fix escapes the header value before inserting it into the generated HTML. Upgrade to `@sveltejs/kit` version 3.0.0 or later.\n\n### Workarounds\n\nAvoid forwarding untrusted `cache-control` header values with `setHeaders` on prerendered pages. Use a fixed, trusted cache policy instead.","affected":[{"package":{"name":"@sveltejs/kit","ecosystem":"npm","purl":"pkg:npm/%40sveltejs/kit"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.0.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-27mw-82g8-phjj/GHSA-27mw-82g8-phjj.json"}}],"references":[{"type":"WEB","url":"https://github.com/sveltejs/kit/security/advisories/GHSA-27mw-82g8-phjj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-114061"},{"type":"WEB","url":"https://github.com/sveltejs/kit/commit/d9d55b579743c80ee7cb59c272d864fd9253dae7"},{"type":"PACKAGE","url":"https://github.com/sveltejs/kit"},{"type":"WEB","url":"https://github.com/sveltejs/kit/releases/tag/@sveltejs/kit@3.0.0"},{"type":"WEB","url":"https://www.vulncheck.com/advisories/sveltekit-before-3.0.0-xss-via-cache-control-header-in-prerendered-pages"}],"database_specific":{"cwe_ids":["CWE-79"],"github_reviewed":true,"github_reviewed_at":"2026-10-23T20:43:30Z","nvd_published_at":null,"severity":"LOW"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:N"}]}