{"id":"CVE-2025-32388","aliases":["GHSA-6q87-84jw-cjhp"],"url":"https://o3.security/vulnerability/CVE-2025-32388","summary":"SvelteKit allows XSS via tracked search_params","details":"### Summary\n\nUnsanitized search param names cause XSS vulnerability. You are affected if you iterate over all entries of `event.url.searchParams` inside a server `load` function. Attackers can exploit it by crafting a malicious URL and getting a user to click a link with said URL.\n\n### Details\n\nSvelteKit tracks which parameters in `event.url.searchParams` are read inside server `load` functions. If the application iterates over the these parameters, the `uses.search_params` array included in the boot script (embedded in the server-rendered HTML) will have any search param name included in unsanitized form.\n\n`packages/kit/src/runtime/server/utils.js:150` has the `stringify_uses(node)` function which prints these out.\n\n### Reproduction\n\nIn a `+page.server.js` or `+layout.server.js`:\n\n```js\n/** @type {import('@sveltejs/kit').Load} */\nexport function load(event) {\n  const values = {};\n\n  for (const key of event.url.searchParams.keys()) {\n    values[key] = event.url.searchParams.get(key);\n  }\n}\n```\n\nIf a user visits the page in question via a link containing `?</script/><script>window.pwned%3D1</script/>`, the `</script>` will be included verbatim in the payload, causing the embedded script to be executed.\n\nIt is not necessary to return the parameter value from `load` or render it in the page, only to read it (which causes it to be tracked as a dependency) while `load` is running.\n\n### Impact\n\nAny application that iterates over all values in `event.url.searchParams` in a `load` function in `+page.server.js` or `+layout.server.js` (directly or indirectly) is vulnerable to XSS.","published":"2025-04-15T22:32:06.059Z","modified":"2026-08-12T03:51:46.233871295Z","cvss":{"score":5.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@sveltejs/kit","fixedVersion":"2.20.6"}],"fix":{"url":"https://github.com/sveltejs/kit/commit/d3300c6a67908590266c363dba7b0835d9a194cf","label":"sveltejs/kit@d3300c6"},"references":[{"type":"WEB","url":"https://github.com/sveltejs/kit/releases/tag/%40sveltejs%2Fkit%402.20.6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/32xxx/CVE-2025-32388.json"},{"type":"ADVISORY","url":"https://github.com/sveltejs/kit/security/advisories/GHSA-6q87-84jw-cjhp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-32388"},{"type":"FIX","url":"https://github.com/sveltejs/kit/commit/d3300c6a67908590266c363dba7b0835d9a194cf"},{"type":"PACKAGE","url":"https://github.com/sveltejs/kit"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:46.233871295Z"}}