Svelte 4.2.12 represents a minor update to the popular Svelte JavaScript framework, building upon the solid foundation of version 4.2.11. While the core functionalities and dependencies remain largely consistent between the two versions, evidenced by identical dependency and devDependency listings including vital tools like rollup, esbuild, typescript, and testing libraries like vitest and @playwright/test, the key difference lies in the release date. Svelte 4.2.12 was released on February 23, 2024, a week after version 4.2.11, which was released on February 15, 2024.
Developers should interpret this as a patch release addressing potential bugs or minor improvements identified in the preceding version. Although specifics of the changes aren't detailed within the provided metadata, such updates typically focus on enhancing stability, addressing edge cases, or optimizing performance without introducing breaking changes.
For developers already using version 4.2.11, upgrading to 4.2.12 is generally recommended to benefit from these refinements. Before upgrading, users should review the Svelte changelog or release notes available on the official Svelte website and GitHub repository. While the identical dependency lists suggest compatibility is maintained, it's always prudent to test the updated version within their specific project context to ensure a seamless transition, taking special care when using edge cases, functionalities or integrations. These minor releases are crucial steps in the continuous improvement of a web development framework, improving stability and performance.
All the vulnerabilities related to the version 4.2.12 of the package
Svelte has a potential mXSS vulnerability due to improper HTML escaping
A potential XSS vulnerability exists in Svelte for versions prior to 4.2.19.
Svelte improperly escapes HTML on server-side rendering. It converts strings according to the following rules:
" -> "& -> &< -> <& -> &The assumption is that attributes will always stay as such, but in some situation the final DOM tree rendered on browsers is different from what Svelte expects on server-side rendering. This may be leveraged to perform XSS attacks. More specifically, this can occur when injecting malicious content into an attribute within a <noscript> tag.
A vulnerable page (+page.svelte):
<script>
import { page } from "$app/stores"
// user input
let href = $page.url.searchParams.get("href") ?? "https://example.com";
</script>
<noscript>
<a href={href}>test</a>
</noscript>
If a user accesses the following URL,
http://localhost:4173/?href=</noscript><script>alert(123)</script>
then, alert(123) will be executed.
XSS, when using an attribute within a noscript tag