CVE-2025-32388 – @sveltejs/kit

Package

Manager: npm
Name: @sveltejs/kit
Vulnerable Version: >=2.0.0 <2.20.6

Severity

Level: Medium

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

EPSS: 0.00052 pctl0.16115

Details

@sveltejs/kit vulnerable to Cross-site Scripting via tracked search_params ### Summary Unsanitized 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. ### Details SvelteKit 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. `packages/kit/src/runtime/server/utils.js:150` has the `stringify_uses(node)` function which prints these out. ### Reproduction In a `+page.server.js` or `+layout.server.js`: ```js /** @type {import('@sveltejs/kit').Load} */ export function load(event) { const values = {}; for (const key of event.url.searchParams.keys()) { values[key] = event.url.searchParams.get(key); } } ``` If 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. It 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. ### Impact Any 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.

Metadata

Created: 2025-04-14T19:10:42Z
Modified: 2025-04-16T00:40:49Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/04/GHSA-6q87-84jw-cjhp/GHSA-6q87-84jw-cjhp.json
CWE IDs: ["CWE-79"]
Alternative ID: GHSA-6q87-84jw-cjhp
Finding: F008
Auto approve: 1