Svelte is a UI framework known for its "disappearing" nature, shifting the workload from the browser to the compile step. Comparing versions 1.18.0 and 1.17.2, reveals minimal, almost negligible development dependency updates, with the core essence and offering to developers remaining consistent. Both versions share the same suite of development dependencies, encompassing tools for testing (mocha, nyc, jsdom), linting (eslint), bundling (rollup), and Babel-based transpilation. The build system relies heavily on Rollup and Babel, ensuring compatibility across diverse JavaScript environments. The inclusion of css-tree suggests capabilities for CSS parsing and manipulation during compilation, a crucial aspect for component styling.
The core value proposition of Svelte during this period remained its ability to compile components into highly optimized vanilla JavaScript, boosting runtime performance by minimizing the browser's workload. Developers could continue to leverage Svelte's component-based architecture for building reactive user interfaces. The consistent dependency list implies a stable developer experience, focused on refining existing features rather than introducing radical changes. For developers, this means a reliable tool for creating performant web applications with efficient compilation and a familiar development workflow. The absence of significant dependency upgrades suggests a focus on stability and incremental improvements within the framework's core functionality. The release date for version 1.18.0 is slightly newer than version 1.17.2, indicating a recent update with potential bug fixes or minor enhancements under the hood.
All the vulnerabilities related to the version 1.18.0 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