GHSA-rjjv-87mx-6x3h @sveltejs/kit vulnerable to XSS on dev mode 404 page

• npm @sveltejs/kit: < 2.8.3 → fixed in 2.8.3

Summary "Unsanitized input from *the request URL* flows into `end`, where it is used to render an HTML page returned to the user. This may result in a Cross-Site Scripting attack (XSS)." Details Source of potentially tainted data is in `packages/kit/src/exports/vite/dev/index.js`, line 437. This potentially tainted data is passed through a number of steps (which I could detail if you'd like) all the way down to line 91 in `packages/kit/src/exports/vite/utils.js`, which performs an operation that Snyk believes an attacker shouldn't be allowed to manipulate. Another source of potentially tainted data (according to Snyk) comes from `‎packages/kit/src/exports/vite/utils.js`, line 30, col 30 (i.e., the `url` property of `req`). This potentially tainted data is passed through a number of steps (which I could detail if you'd like) all the way down line 91 in `packages/kit/src/exports/vite/utils.js`, which performs an operation that Snyk believes an attacker shouldn't be allowed to manipulate. PoC Not provided Impact Little to none. The Vite development is not exposed to the network by default. And even if someone were able to trick a developer into executing an XSS against themselves, a development database should not have any sensitive data.