Svelte 3.42.1 is a minor patch release following closely on the heels of Svelte 3.42.0, both dedicated to enhancing the developer experience and stability of this popular JavaScript framework. The core description remains consistent: "Cybernetically enhanced web apps," highlighting Svelte's focus on performance and a streamlined development process. Examining the metadata, both versions share identical development dependencies, indicating no substantial changes in the tooling or build process. This suggests that the update from 3.42.0 to 3.42.1 likely addresses bug fixes or minor improvements rather than introducing new features or altering the core architecture.
A subtle difference is observed in the dist section; while both versions contain 229 files, the unpackedSize of 3.42.1 is marginally larger at 6921967 bytes compared to 3.42.0's 6921745 bytes. This small size increase could be attributed to resolved bugs, optimized code snippets, or very minor updates to the build output within existing files. The releaseDate confirms that 3.42.1 was released shortly after 3.42.0, solidifying its role as a quick follow-up to patch any immediate issues. Developers should upgrade to 3.42.1 for increased stability and to ensure they are using the most refined version available, especially if they encountered any minor issues with the previous release. This incremental update delivers the same core Svelte experience with subtle improvements which makes it perfect for building incredibly fast web applications removing the bloat associated with traditional frameworks.
All the vulnerabilities related to the version 3.42.1 of the package
Svelte vulnerable to XSS when using objects during server-side rendering
The package svelte before 3.49.0 is vulnerable to Cross-site Scripting (XSS) due to improper input sanitization and to improper escape of attributes when using objects during SSR (Server-Side Rendering). Exploiting this vulnerability is possible via objects with a custom toString() function.
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