Svelte 1.56.4 offers a minor update over its predecessor, version 1.56.3, primarily focusing on internal improvements and bug fixes rather than introducing major new features directly impacting developers. Both versions, however, represent a mature stage of the Svelte 1.x series, a time when the framework was already lauded for its compiler-first approach, enabling it to vanish as a dependency in production by transforming code into highly optimized vanilla JavaScript.
Developers transitioning from 1.56.3 to 1.56.4 can anticipate slightly refined performance and enhanced stability. Under the hood, the updated release likely involves tweaks to the compiler, potentially resulting in smaller bundle sizes or faster rendering speeds. The extensive list of devDependencies, common across both versions, highlights the ecosystem of tools Svelte leverages during development, showcasing a commitment to modern practices, like linting with ESLint, bundling with Rollup, and type-checking with TypeScript.
Given the patch version increment, the upgrade from 1.56.3 is recommended for all users to benefit from the latest refinements, especially those encountering edge-case issues. While the core developer experience remains consistent, embracing the newest patch ensures integration with the most polished and reliable iteration of Svelte 1.x, an excellent choice to build reactive components.
All the vulnerabilities related to the version 1.56.4 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