Svelte 3.27.0 is a minor version increment over 3.26.0 in the popular JavaScript framework for building user interfaces. Both versions share the same core philosophy of cybernetically enhanced web apps, empowering developers to create highly performant and reactive web experiences. Looking at the surface, most of the development dependencies remain consistent like rollup, typescript, and linting tools. This indicates a continued focus on maintaining a stable and consistent development environment for Svelte contributors.
The key difference between the versions lies in the dist object. Svelte 3.27.0 features a slightly larger unpacked size of 5956336 bytes compared to 5915851 bytes in 3.26.0. This small increase could be attributed to bug fixes or minor feature additions. The release date indicates that version 3.27.0 was released just two days after 3.26.0 suggesting that possibly a fix or a small feature was released in between. For developers already using Svelte, this minor update likely includes subtle improvements. Keeping up to date with the last versions ensures you are getting the latest bug fixes and improvements of the framework with a more typesafe and consistent web app developer experience. These incremental updates contribute to the ongoing refinement and optimization of the Svelte compiler, providing developers with a smoother and more efficient development experience.
All the vulnerabilities related to the version 3.27.0 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