Svelte is a UI framework conceived to make web development more performant and streamlined. Version 1.12.0 introduces subtle refinements and improvements compared to the previous stable version, 1.11.4, maintaining compatibility, as reflected in the unchanged dependency on magic-string at ^0.19.0. While the core development dependencies remain largely consistent, encompassing tools like rollup for bundling, babel for JavaScript transformation, and eslint for code linting, the new release signals an effort toward stability and continuous integration, rather than groundbreaking feature additions.
Developers familiar with Svelte will find upgrading straightforward. The unchanged dependency list suggests API stability, minimizing the likelihood of breaking changes. The updated release signifies ongoing maintenance and bug fixes, meaning a potentially more reliable developer experience. Key tools like Rollup, Babel, and ESLint ensure a modern development workflow, while testing frameworks like Mocha and code coverage tools like Codecov highlight the project's commitment to quality. The presence of various Babel plugins, targeting ES2015 transformations, emphasizes support for modern JavaScript features while maintaining broad compatibility. For developers, this small version increment translates into a more refined and robust foundation for building performant web applications. The update prioritizes stability and a gently improved development environment.
All the vulnerabilities related to the version 1.12.0 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