Svelte version 1.51.1 is a minor patch release following quickly after version 1.51.0, both iterations of the "magical disappearing UI framework." Examining the metadata, the core functionalities and dependencies remain largely unchanged between the two versions. Both leverage the same suite of development tools, including Rollup for bundling, TypeScript for enhanced code quality, and ESLint for linting. Developers migrating between these versions shouldn't expect any breaking changes or significant API alterations. The consistent dependency list signals a focus on stability and refinement rather than groundbreaking feature additions.
The key difference lies in the release date: version 1.51.1 was published on January 11, 2018, just a few days after version 1.51.0 which was released on January 6, 2018. This short interval strongly suggests that version 1.51.1 addresses critical bugs or minor imperfections present in the preceding release. While the specific fixes are not detailed in this data, it is highly recommended for developers using 1.51.0 to upgrade to 1.51.1 in order to benefit from improved stability and reliability. New projects should directly utilize version 1.51.1 to ensure they are built upon the most up-to-date and refined codebase within this patch series. In essence, upgrading to 1.51.1 is a worthwhile decision.
All the vulnerabilities related to the version 1.51.1 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