Svelte is a radical approach to building user interfaces, shifting the workload from the browser to the compiler. Versions 1.6.6 and 1.6.5 showcase this philosophy, offering developers a performant and efficient way to create web applications. Examining the package data, the core dependencies remain consistent between these two minor releases, with magic-string handling source code manipulation. The list of devDependencies is extensive, hinting at the comprehensive testing and build processes Svelte undergoes. Tools like rollup, eslint, mocha, and nyc ensure code quality, bundling efficiency, and thorough testing.
The key difference between versions 1.6.6 and 1.6.5 lies in their release dates and potentially internal bug fixes or minor improvements that aren't explicitly detailed in this metadata. Version 1.6.6 was released on January 24, 2017, about a week after 1.6.5, which was released on January 18, 2017. For developers, this suggests a rapid iteration cycle focused on stability and refinement. While the feature set appears identical, upgrading from 1.6.5 to 1.6.6 would likely provide a more polished and reliable experience. Svelte's "disappearing UI framework" promise means less code shipped to the browser, resulting in faster load times and improved performance for end-users. Both versions offer this benefit, but the newer release typically incorporates crucial fixes, making it the preferred choice for new projects and existing applications. Developers should always prioritize the latest stable version for optimal performance and bug fixes when building with Svelte.
All the vulnerabilities related to the version 1.6.6 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