Svelte version 1.30.0 introduces incremental improvements over the previous stable version, 1.29.3, continuing its evolution as a "magical disappearing UI framework". While the core description remains consistent, the underlying changes focus on refining the development experience and potentially addressing minor bugs or performance bottlenecks. Examining the devDependencies section reveals that both versions share an identical suite of tools, including popular choices such as Rollup for bundling, ESLint for code linting, and TypeScript for enhanced type safety. This indicates a stability in the development workflow and a commitment to maintaining compatibility with existing toolchains.
The release of version 1.30.0, just two days after 1.29.3, suggests a swift response to user feedback or the quick resolution of a discovered issue. Developers upgrading from 1.29.3 can expect a seamless transition, with the potential for subtle performance enhancements or bug fixes. Svelte's appeal lies in its compiler-based approach, translating declarative components into highly efficient vanilla JavaScript, leading to improved runtime performance and smaller bundle sizes. These improvements make Svelte especially attractive for building fast and lightweight web applications with a focus on user experience. If you're already using Svelte, this is a recommended upgrade; if you're looking for a framework that minimizes overhead, Svelte remains a compelling choice.
All the vulnerabilities related to the version 1.30.0 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