Svelte is a UI framework known for its "disappearing" nature, meaning it compiles your code into highly efficient vanilla JavaScript at build time. Comparing versions 1.53.0 and 1.54.0, developers will find subtle improvements primarily impacting the development environment. Both versions share the same core dependencies, ensuring a consistent experience when building Svelte applications. Key devDependencies like Rollup, Typescript and ESLint remain consistent, suggesting no major fundamental architectural shifts between the two releases.
The primary difference lies within the jsdom dependency, upgraded from version 11.1.0 in 1.53.0 to 11.6.1 in 1.54.0. This change is relevant for developers relying on jsdom for server-side rendering (SSR) or testing Svelte components in a Node.js environment. The upgrade likely addresses bug fixes and performance improvements within jsdom itself, contributing to a more reliable testing and SSR setup. While the core Svelte compilation process appears unchanged, version 1.54.0 offers a potentially smoother development experience, particularly where jsdom integration is involved. Developers should investigate the jsdom changelog for specific fixes or new features relevant to their projects. Both versions are licensed under MIT and authored by Rich Harris, ensuring continuity and community support. Ultimately, the choice between versions depends on project-specific needs and jsdom dependency requirements.
All the vulnerabilities related to the version 1.54.0 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